I think it depends on the person.

I know for myself that symptoms will set in at pretty much three weeks. After 5 embryo transfers and 4 pregnancies, it's pretty obvious when things start changing. Things start changing for me somewhere between 3 and 5 days after embryo transfer, which would equate to 7-10 days after ovulation in someone not using assisted conception. The cycle that gave as Samuel I was experiencing fairly extreme nausea well before any pregnancy test would work.

Some would say that it's the drugs used as part of IVF that do it - but most of my transfers had no luteal phase support, and it was pretty obvious that there were no symptoms at all on the one that didn't take. I know my body reacts as soon as implantation even starts to occur.

BW