For me, it was immediate - but I had a mild case of OHSS on top of my retroverted uterus!

Once the OHSS went down, it was probably closer to 15 weeks before a pg belly even started to show, even though I'd been in pants a size larger from the moment AF was due.

I didn't get really big until closer to 30 weeks, though. Up until that point it wasn't really obvious that I was pregnant at all - but that could have been due to the way I dress and the fact that babydoll tops seemed to be in then.

BW