Contractions?

Okay with my first, I didn’t have Braxton Hicks (or I didn’t feel them) and I had back labor, then had an epidural and seriously felt no contractions, so I have no clue what they feel like! I’m 37 weeks with my second and I have constant back pain but it’ll get dull and move around to the front, slightly taking my breath away and my belly tightens but not all over. Is this a contraction? Not painful, just uncomfortable! Just wanna be sure so I can start timing them! Sometimes there’s a cramping sensation & sometimes there’s not.