Real or false labor?

I'm 39 weeks 4 days and have been having contractions/ horrible back pain/ lower sharp pains since the 2nd. I took a hot bath twice to see if that would help make the contractions go away if they weren't real labor contractions and it didn't. When I pee, it's the worst pain ever down low! I can't even walk straight because of the sharp pains. This is my first pregnancy so I have no clue what should be hurting and what shouldn't..