Pregnancy Week-by-Week Tracker
Enter your due date or the first day of your last period to see how far along you are, your trimester, and a countdown — plus a short checklist of the decisions worth making before your baby arrives. Everything stays on your device.
Enter the date your provider gave you.
Enter a date to see your current week, trimester, and countdown.
What to decide, and when
The money and legal decisions worth handling before your baby arrives. Tick them off as you go — your ticks are saved here too.
Weeks 12–20 · Get your safety net in place
You are past the earliest weeks — a good moment to size life insurance while cover is cheap and easy to buy.
Weeks 20–28 · Put the paperwork in place
The mid-pregnancy stretch is when most parents draft a will and decide who would raise their child if they could not.
Weeks 28+ · Set up the money that compounds
In the third trimester, lock in the savings decisions — a college fund started now has eighteen years to grow.
Educational estimate only — not medical advice. Dating is approximate; your provider’s dates are authoritative.
How the dating works
Obstetric dating counts a pregnancy as forty weeks — 280 days — from the first day of your last menstrual period, not from conception (which happens about two weeks later). That is why you can be “six weeks pregnant” only four weeks after conceiving. This tracker uses the same convention: give it your due date and it counts back to that starting point and forward to today; give it your last period and it adds 280 days to estimate the due date first, then does the same math.
Trimesters follow the usual split: the first runs through week 13, the second from week 14 to 27, and the third from week 28 to birth. An early-ultrasound due date is generally more reliable than counting from a last period, especially with irregular cycles, so prefer it if you have one. The result is an estimate for planning — your provider’s dates always win.
How to use the checklist
The point of the tracker is not just the number of weeks — it is doing the few decisions that protect your family while there is still time to do them calmly. We map them to the phase of pregnancy when most parents have the space to act: weeks 12–20, size your life insurance while cover is cheap and easy to buy; weeks 20–28, draft a will and choose a guardian; weeks 28 and beyond, open or finalize a college savings plan so it has eighteen years to grow. Tick each item as you handle it. The phase you are currently in is highlighted, and your ticks are saved on this device so the list is waiting where you left it next time.
None of this is urgent on any single day, which is exactly why it slips — so treat the highlighted phase as a gentle nudge rather than a deadline. Each item links straight to the HarborPlain tool or guide that gets it done, so you can go from “I should sort that out” to a concrete next step in a couple of clicks.
Frequently asked questions
Pregnancy is dated as 40 weeks (280 days) from the first day of your last menstrual period. If you enter your due date, we count back to that start point and forward to today; if you enter your last period, we add 280 days to estimate the due date first. It is the same convention your provider uses, so the numbers should line up closely.
If your provider has given you a due date, especially one confirmed by an early ultrasound, use that. Ultrasound dating is generally more accurate than counting from a last period, particularly if your cycles are irregular. Either way, this is an estimate for planning — your provider's dates are the authoritative ones.
Only on the device you are using, in your browser's local storage, so the tracker remembers your week when you come back. Nothing is sent to our servers, and you can clear it any time with the Reset button. Weekly email reminders are an optional feature we are adding later — until then there is nothing to opt into.
Because the calmest time to make those decisions is before the baby arrives, not after. The checklist points to the few high-value tasks — sizing life insurance, naming a guardian, starting a college fund — mapped to the phase of pregnancy when parents typically have the time and headspace to handle them.
The tracker keeps working right up to and a little past your due date, since going a week or two over is common. If the date is well in the past, it assumes the baby has arrived and invites you to enter a current pregnancy instead.
Educational estimate only — not medical, financial, or legal advice. Pregnancy dating is approximate; always follow the dates and guidance your healthcare provider gives you.