Braxton hicks or labor contractions?

My lower back has been hurting all day. There’s not a moment where it hasn’t stopped. I’ve also been having some pelvic bone pain and hurting in my upper thighs and vagina (no pressure just intense pain). I’ve tried warm baths and a warm shower but it has not soothed it.

Can someone describe the difference between BH vs labor contractions? Im currently 34 weeks.