I'm 16+4 weeks pregnant and all been well so far! I have had the occasional painful, uncomfortable twinge around the uterus and pelvic area. (Mainly when I'm walking or standing) Yesterday I was walking home from work and I got this same pain, really uncomfortable and heavy, almost like a pullin feeling. I had to walk home really slowly as it was almost unbearable to walk!
Once I got home and sat down it was fine so in total only lasted about 10 mins.