Contractions vs Braxton hicks

I woke up at 6 am to a sharp pain where my right abdomen and pelvis meets. The pain shot upwards and then I started contracting on the right side. It was very painful to move my leg or anything on the right side. It's 9:30 and I'm still contracting from the lower back but they aren't as painful as the first one but it's bothersome enough to keep me from sleeping. I'm just curious as to when I should go to L&D I'm  31 weeks and baby is moving. I've been to the hospital several times for other reasons but I don't wanna go if these are just Braxton hicks.