Pelvic pressure

I'm in my 18th week and this morning woke up with bad pelvic pressire/discomfort. Stomach was tightening up a lot the past two days. Contracting? I talked to the nurse this afternoon and she said to go into labor and delivery if I needed to even if just for peace of mind. Obviously, if there's bleeding or discharge to go in. Anyone have any experience or can give any thoughts/advice? It's really stressing me out.