Labor or body just preparing?

I'm a FTM 35+4 and lost part of my mucus plug on Sunday. Since then, I've had some pretty good braxton hicks that are getting a little more regular. I'm not having more than 4 an hour though but they're consistent through out the day. Today, I've been pretty nauseous and having lots of lower back pain and lower pelvic pain. Am I in labor or is my body just preparing?