Implantation

Implantation is the process by which a blastocyst attaches to and burrows into the endometrium, usually around six to ten days after fertilisation. Once implantation begins, the developing placenta starts producing hCG, which is what a pregnancy test detects. Implantation cannot be seen or felt reliably, and symptoms in the two-week wait do not predict whether it has happened.

Also known as: embryo implanting, embedding

Last reviewed: 10 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.