I started feeling mine faily early on with my last pg, about 16ish weeks I think. Early in the pg they were just tightenings. My tummy would go hard for a few seconds and would make it kinda hard to do stuff like bend or move too much. They usually only came when I was exerting myself too much. Later on they slowly started to get painful and quite ouchy regularly and like Kim, I was in labour and didn't realise it because I just thought it was my BH! Luckily I got to hossy when I was 8cm dialated! I just went in for some pain relief so I could sleep, lol!