3rd pregnancy, 20 weeks and a lot of pressure

First, let me start by saying that im waiting for my doctor to call me back. I just want to see if anyone has any input while I wait. 
So, this is my third pregnancy and I am 20 weeks today. I am feeling a ton of pressure! In my lower tummy and also inside my lady parts. I also feel swollen up in there. I don't remember feeling this way this early with my other too pregnancies. 
I've also had an increase in clear mucus like discharge and a little bit of cramping here and there. 
Normal? Or something I should be worried about?