Can AI build a pregnancy tracker app like Ovia?

Build a personal pregnancy tracker web app to replace Ovia for my own use.

Tech rules:
- Plain HTML, CSS, and vanilla JavaScript in one file. No framework, build step, account, or server.
- Store all data in localStorage under one key, with a version number.

Data model:
- Pregnancy: id, lastPeriodDate, ultrasoundDueDate (optional, overrides last-period estimate if set), isMultiples (boolean), status (active, postpartum, ended).
- LogEntry: id, date, weight, weightUnit, mood, symptoms [], notes.
- KickSession: id, date, startAt, kickTimestamps [], targetCount.
- Milestone: id, week, note (user-entered, not pre-populated content).

Features:
- Enter last period date or an ultrasound-confirmed due date; the app calculates current week and trimester from whichever is set, with the ultrasound date taking priority when both exist.
- Weight, symptom, and mood logging with a simple form, viewable as a timeline across the full pregnancy.
- A kick counter: tap once per kick, showing a running count that resets each day, with the time to reach a target count (for example 10 kicks) shown once reached.
- A postpartum mode: after entering a birth date, the app switches from "week X of pregnancy" display to a simple postpartum day counter, without deleting pregnancy history.
- Support for multiples: one due date, but the option to log symptoms and notes tagged per baby if desired.
- No required location or state field anywhere in the app.

Edge cases the build must handle correctly:
1. Due date recalculates correctly when switching between last-period dating and ultrasound dating, always preferring the ultrasound date once entered.
2. Week and trimester display logic works correctly across a full, variable-length pregnancy (37 to 42 weeks).
3. Weight, symptom, and mood logs remain viewable as one continuous timeline across 40+ weeks without performance issues.
4. The kick counter resets correctly at the start of each new day, with no kicks carried over.
5. Entering a birth date correctly switches the app into postpartum mode without deleting or hiding prior pregnancy log entries.
6. If a loss is recorded instead of a birth, the app handles the transition without breaking the timeline UI or forcing further pregnancy-specific prompts.
7. Multiples (twins, triplets) share one due date and one pregnancy record, with optional per-baby tagging on logs.
8. No screen in the app requires entering a location, state, or country to function.

Backup:
- One-click "Export JSON" and "Export CSV" of all logs and milestones.
- "Import JSON" restores after confirmation.

Layout:
- Mobile-first, readable at 375px wide, simple one-handed logging.

Exclusions:
- No publishing, App Store submission, accounts, payments, social features, weekly content library, or any location or region field.

Write a short README explaining where data is stored, how to export and restore it, and that no data leaves the device.

Keep it under 600 lines. This is a personal tool, not a product.

What is the short answer?

Yes, but. Ovia Cycle & Pregnancy Tracker is free to download and use, with no consumer in-app purchases listed on its App Store page. AI can build a comparable due-date, symptom, and kick-counter tracker in a weekend.

The “but” is that there’s no subscription to cancel here. Most Ovia users have nothing to personally cancel: the consumer app is free, and its Ovia+ premium tier is typically paid for by an employer or health plan, not the person tracking the pregnancy. The actual reason to build your own is privacy. Ovia Health has drawn documented press scrutiny, including 2019 reporting on sharing aggregated employee data with employers and 2024 coverage of its required state and country field, that a private, self-built tracker sidesteps entirely. Build it for control over your data, not to save money.

Option	Best for	Upfront cost	Ongoing cost	Main limitation
Build a rough prototype	Someone who wants a private due-date and symptom log without Ovia’s account	$0 and 3–4 hours	$0	No weekly content, no polish yet
Build a daily-use personal version	Someone who wants full logging, kick counter, and postpartum mode, fully private	$0 and 10–12 hours	$0	Still no medically-reviewed weekly content library
Keep paying for Ovia (it’s free, so $0 either way)	Someone who wants Ovia’s weekly content and doesn’t mind its data practices	$0	$0	Documented data-sharing scrutiny and a required location field

The ready-to-paste starter prompt at the end of this page builds the daily-use version.

What should the first version include?

The first version needs the calculations right before anything else, since due-date math is the one thing that has to be correct.

• Due date from last period or ultrasound dating
• Week and trimester display
• Weight, symptom, and mood logging
• A kick counter with daily reset
• Postpartum transition after birth
• Deliberate exclusion: no weekly content library, no location field. Content takes real research; location was never necessary for a personal tool.

What can AI build reliably?

ChatGPT and Claude build due-date math, logging forms, and a kick counter reliably. These are date calculations and simple structured logs, well within a single conversation’s scope.

Concrete things AI gets right:

• Correct week and trimester calculation from either dating method
• A continuous weight, symptom, and mood timeline across a full pregnancy
• A kick counter that resets daily and tracks time-to-target
• A postpartum mode switch that preserves prior history

Where will AI need human help?

The transition moments need your review. Postpartum transition, and handling a loss without breaking the timeline UI, are sensitive edge cases AI’s first draft may handle clumsily, showing pregnancy-specific prompts after they no longer apply. Test these transitions yourself before relying on the app during an emotionally difficult time.

Multiples need explicit handling too. If you’re expecting twins or triplets, confirm the app correctly shares one due date while still letting you log symptoms or notes per baby if you want that distinction.

The decision only you can make is how much weekly content to add yourself. Reproducing Ovia’s medically-reviewed fetal size comparisons and articles takes real research or licensing, not just a database schema, so most personal builds should skip this rather than write medical content casually.

Privacy is the main point of this build, so treat it seriously: no account, no analytics, no required location field, and think carefully before syncing this data anywhere else.

Can I get my data out of Ovia?

Yes. In-app: More > Settings > Export my data. Ovia emails a .zip file containing several CSV spreadsheets of data logged or viewed in the app, plus any uploaded photos or videos. This is available to all users on the free app, no paid plan required.

The export trap: the export is several raw CSV files rather than one clean pregnancy timeline, mixing tracked health data with article and content view history, so a rebuild has to filter and merge files instead of importing a single dataset. Third-party sources, not Ovia’s own help page, claim the emailed download link expires after about 7 days [VERIFY].

The practical path: request the export promptly, download it within that window, and use only the health-tracking CSVs (symptoms, cycle, ovulation data) rather than the article-view history when importing into your new app.

How long will it take and what will it cost?

Rough prototype: 3–4 hours and $0. Due-date math, week and trimester display, and basic logging.

Dependable daily-use version: 10–12 hours, including the kick counter, weight and symptom timeline, and postpartum transition. Build it on a free AI plan.

There’s no break-even math here, since Ovia itself costs nothing. The only cost comparison that matters is your time against the privacy and control you gain by not using an app with documented data-sharing scrutiny in its B2B arm.

These are estimates from reviewing the feature set, not measurements from a completed build.

Which AI tool or approach should I use?

Claude or ChatGPT on a free plan handles the due-date logic, logging, and kick counter comfortably.

Cursor isn’t necessary for a build this size.

Lovable isn’t a good fit either, since adding a hosted backend for a pregnancy tracker reintroduces exactly the kind of third-party data handling this build is meant to avoid.

What will I need to maintain?

Minimal. One or two files on a free static host.

Recurring work:

• Export a JSON or CSV backup every few weeks during pregnancy, when data changes fastest
• Switch the app into postpartum mode once, after birth
• Reopen the app online occasionally so any cached version stays current

Should I build it, buy it, or reduce scope?

Build it if privacy is your priority and you don’t need a weekly content library of articles and fetal size comparisons.

Buy it, or rather, keep using Ovia, if its free weekly content and community features matter to you and the documented data-sharing scrutiny doesn’t concern you enough to change apps.

Reduce scope if you just want a due-date countdown. Any basic calendar app or even a paper calendar covers that without building anything.

Recommendation: build it if privacy and control over your pregnancy and location data matter to you, since Ovia costs nothing either way and the money argument doesn’t apply. Keep using Ovia if its weekly content genuinely helps you and you’re comfortable with its documented history. If you’re also tracking cycles before or after pregnancy, see the Flo-style cycle tracker build, and for ongoing sleep tracking postpartum, see the sleep tracker build.

What if I wanted to ship this to other people?

Shipping a pregnancy tracker to other people means licensing or writing a full medically-reviewed content library, handling sensitive health data at scale with real security and compliance obligations, and competing with a free, well-resourced incumbent. It’s a much bigger project than a private personal tracker, with real liability if medical content is wrong.

Starter build specification

• User: You, for your own use, tracking your own pregnancy privately.
• Problem: Wanting a private due-date, symptom, and kick-counter tracker without Ovia’s documented data-sharing history or required location field.
• Core workflow: Enter dating information, log weight and symptoms through the pregnancy, use the kick counter in the third trimester, transition to postpartum mode after birth.
• Required features: Due-date math from 2 dating methods, week and trimester display, symptom and weight logging, kick counter, postpartum transition, no location field.
• Deliberate exclusions: No weekly content library, no accounts, no location or region requirement, no social features.
• Data ownership: Stored in localStorage. Exported as JSON and CSV. Imported from JSON.
• Definition of done: Switching between last-period and ultrasound dating recalculates the due date correctly, the kick counter resets daily, and entering a birth date switches the app to postpartum mode without losing pregnancy history.

For scoping help, read can AI build an app for me.

Sources and verification

• Ovia Cycle & Pregnancy Tracker (App Store): free download, no listed consumer in-app purchases.
• Ovia Health Pregnancy App: feature overview of the free consumer app.
• How Do I Export My Data? (Ovia Help Center): the in-app export flow.
• Pregnancy Tracking App Raises Privacy Concerns Over Data Shared With Employers (Becker’s Hospital Review): 2019 reporting on Ovia’s B2B data practices.
• Pregnancy App Maker Ovia Health Is Selling Data to Employers (ConsumerAffairs): further 2019 coverage.
• Ovia App Location Requirement Fact Check (Snopes): 2024 confirmation that Ovia apps require a state or country field.

This app was not built and tested for this page. The verdict is based on Ovia’s own site and App Store listing, its help center export documentation, and press coverage of its B2B data practices. Ovia’s price was checked on September 24, 2026.

Reviewed on September 24, 2026.