Constant braxton hick?

For a few hours it feels like I’ve been having one giant braxton hick. My stomach tensed up for one this morning. The shortness of breath went away but my stomach has been hard as a rock ever since. It’s so uncomfortable and I can barely sit up because of how tense it is. This has never happened before. I’m 34 wks and I get them all the time but not like this. Does anyone know what could be going on? Should I call my Ob?