Braxton hicks?

The past 2 days I've had pain in my lower belly that's constant but gets worse and eases at times. This is my second pregnancy but I never had braxton hicks Aswell as other things that didn't happen with my first, my waters didn't break and I didn't lose my plug with her so don't really know what signs to look for. I am only 32 weeks but feel like it's not going to be long as I am ready for popping. Also I have a Low-lying placenta so don't know how different things are going to be. Any advice?