Back aches and cramping

Rachel • 25 years of age -- one angel baby (Emelia Rose) and my rainbow baby born 07/13/15 (Layla Marie). Baby boy due 03/03/2017
I'm 35+5 and have been having this constant back ache for a few days now. I took Tylenol (extra strength) this afternoon and it's back again with a vengeance. I've been cramping too...this would be my first live baby, so is this normal?? My hips have been hurting/achy too. 😓