I've had this happen to me a few times.. What helped was taking a bath, drinking lots and lots of water and just relaxing. If it doesn't go away within a couple hours maybe call the on call nurse or labor and delivery and see what they tell you to do!

yes its constant and I have peed a lot as well

Is it constant? It could just be some Braxton hicks contractions! Or maybe slight dehydration. If I don't drink enough water and go to the bathroom enough my stomach gets hard and feels like it has pressure on it!