Back labor or am I just being paranoid??

So I've been having pretty bad lower back pains for about 3-4 days now. It doesn't come and go, its constant and so far nothing has helped the pain. I'll also have slight menstrual like cramping here and there, along with what I believe are Braxton hicks contractions. Could this be back labor?? I've also heard some women didn't even know they were in labor because they only had back pain. I'm only 31 weeks but don't want to go in and get checked if it's just going to be regular pregnancy pain. 😓 I called labor and delivery lastnight and they told me to come in but I couldn't at the time.