Can't tell!

Deyona
I can't tell if I'm having contractions or if I'm just uncomfortable. It feels like a upset tummy or early period like cramps. But they don't last long. Feels like I have to #2 but then I don't. I've been pretty gassy the last 2 days. And have had slight back pain and lots of pelvic pressure..what should I do?  39 weeks and 5 days btw.