About

In Vitro Fertilization (IVF) protocols differ significantly from natural conception in terms of dating. Standard pregnancy calculations rely on the Last Menstrual Period (LMP), but in IVF, the date of embryo transfer and the age of the embryo (Day 3 cleavage or Day 5 blastocyst) provide a precise mathematical starting point. This precision is critical for managing the "Two Week Wait" (TWW) and understanding when beta-hCG blood tests are reliable.

This tool converts your transfer date into an "Equivalent DPO" (Days Past Ovulation). It generates a personalized calendar highlighting the implantation window and the threshold where urinary hCG concentrations typically exceed the sensitivity of home pregnancy tests (20-25 mIU/mL). It removes the guesswork from converting medical acronyms like 9dp5dt (9 Days Past 5-Day Transfer) into actionable timeline data.

Formulas

The core logic standardizes the timeline to a hypothetical ovulation date.

EqDPO = DaysSinceTransfer + EmbryoAge

GestationalAge = EqDPO + 14 (days)

For example, if you are 9 days past a 5-day transfer (9dp5dt), your equivalent DPO is 14 (9 + 5), which corresponds to exactly 4 weeks pregnant (28 days gestational age).

Reference Data

Event	Timing (Equivalent DPO)	Standard Date	hCG Detectability
Embryo Transfer	DPO 3 or 5	Day 0	None
Implantation Begins	DPO 6 − 7	1 − 2 Days Post Transfer	None
Implantation Complete	DPO 9 − 10	4 − 5 Days Post Transfer	Trace Amounts
Early Positive (Sensitive)	DPO 11 − 12	6 − 7 Days Post Transfer	10 − 20 mIU/mL
Standard Positive	DPO 13 − 14	8 − 9 Days Post Transfer	≥ 25 mIU/mL
Beta Blood Test	DPO 14 +	9 + Days Post Transfer	≥ 50 mIU/mL

Frequently Asked Questions

A 3-Day embryo is at the cleavage stage, while a 5-Day embryo has reached the blastocyst stage. Because the 5-Day embryo is more developed, it implants sooner after the transfer. The calculator adjusts for this by adding the embryo age to the days past transfer.

While implantation typically finishes by 9-10 DPO (equivalent), urinary hCG levels lag behind blood levels. The earliest reliable result on a sensitive First Response test is typically equivalent to 11-12 DPO. Testing earlier often results in false negatives.

It stands for "Days Past 5-Day Transfer". It is the standard notation in IVF communities. Similarly, "dp3dt" refers to a 3-Day transfer.

Yes. Most trigger shots contain hCG (e.g., Ovidrel, Pregnyl). This synthetic hCG can linger in your system for 10-14 days, causing a false positive. This calculator assumes the trigger shot has metabolized; always consult your clinic's specific instructions regarding trigger testing.