Fertility basics
Clinics book scans, blood tests and the start of medicines by cycle day, so it matters that day 1 is the first day of proper bleeding, not spotting that comes before it. If bleeding starts late in the evening, many clinics count the following day as day 1 — check what your own clinic prefers.
Also known as: day 1, cd1, day 2 of cycle
Related South Africa guides
Sources
- ESHRE/ICMART glossary of assisted reproductive terminology
Last reviewed: 8 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.