Cramping and Belly Feels Tight

I've got some cramps that feel like Pms cramps. Not terrible. But I'm taking notice. My belly hurts..like it's tight. Sometimes feels like it's being squeezed and I'm nauseous. Started at 4:30 this morning but I fell back asleep. Thought I needed to go to the bathroom. But that didn't help things. 
I will be 38 weeks on Wednesday. I have a doc appointment at 2. I feel like there is no room in my stomach to eat or drink or I'll puke. 
Is this Braxton Hicks? This tightness and cramping?