Stupidest question but..

I’m a ftm and I’m 35 weeks tomorrow and I don’t know what I’m looking for to pin point Braxton Hicks or even regular contractions. I think I’ve been having some Braxton Hicks especially at night, but like I said I’m not 100% sure that’s what it is.

My stomach tightens a lot, sometimes my lower back hurts a lot while this happens and it’s really hard to get comfortable or breathe even. Are these Braxton Hicks and should I be timing or something to make sure they’re not regular?