About
Calm arithmetic for the sticky-note moments
PregDateBase is a small set of free, browser-only date calculators for IVF/FET due dates, reverse conception windows, implantation timing, pregnancy weeks, and light cycle support — not a clinic portal and not another empower-your-journey app.
Last updated: July 17, 2026
What this site is
The point is getting the date straight when the discharge sheet, the patient portal, and a period app disagree. Transfer-day sticky notes, EDD reverse-checks, implantation windows, and week counts — planning math you can show your work on.
Everything is estimate-only. Ultrasound and your clinician’s dating policy win when they disagree with a browser widget. Dates stay on your device; we do not ask for an account.
Trust lives on IVF, reverse, and implantation tools first. Cycle pages and the Chinese gender calendar are support / entertainment tracks — labeled honestly, not sold as science.
Who it’s for
People after embryo transfer who need Day 3 vs Day 5 spelled out; people with an EDD who want an honest conception window; people counting weeks from LMP or transfer without inventing a fake period for an app.
What we will not do
We will not diagnose, prescribe, or promise a delivery day. We will not turn the Chinese gender calendar into science. We will not chase every giant head-term SERP when mode-specific IVF, reverse, and implantation pages tell a clearer story.
How dates are handled
Math runs in your browser. Optional “remember inputs” stays in localStorage on your device. No account wall, no fertility social feed, no journey lecture.
Estimate only — not medical advice. Ultrasound and clinic dating policy override any browser estimate. Confirm medical decisions with your clinician.