Upper abdominal pain?

Yesterday I began to have a slight pang in my upper belly, now it's increased to actually being painful.. 
I was super constipated so it could be that but I'm doing that business now. Usually any poop pain is lower, this is kinda above my uterus.. 
Any ideas on what it could be? I live out of town and don't want to have to make my hubby take the day off work to take me in just for poop cramps..
Also I'm 30 weeks.