Aaah I've just seen this and now I'm really sad!
www.fertilitycenter.com/fertility_cares_blog/intercourse-at-the-time-of-embryo-implantation/
I've had cramps for the last few days (currently day 23), and now I'm worried I've ruined it all by having sex the last 2 days!
Has anyone else seen this? Do you avoid it during the implantation time?