From memory, it was at about 16 weeks. I can remember it was a huge relief because I'd had a bit of abdominal pain and was convinced that something was up. Anyhow, my partner's a shiftworker so often comes to bed at around 2am (the time when the baby is most likely to be moving) so he kept reassuring me that although I may not have felt anything during the day he was feeling little movements while I was asleep! Then of course I got jealous that he was feeling stuff that I couldn't!