I'm about 13.5 weeks and keep getting this tightening, like it feels like my pants are too tight even when i have none on! i am starting to feel my uterus rising about my pubic line but the tighening also feels like a itching,tingling underneath my skin. What is this? also i'm waking with a sore left hip and its a bit sore throughout the day? is it just stretching? i'm a bit worried about the tightening, baby heart ok on doppler.