Yes! You are not alone. I am 15 weeks 2nd pregnancy and I feel a whole lot of pressure too. I dont know why but having a full bladder makes it worse :/
I hope you feel better :) I am kinfa scared because I do wonder what 6 or 8 months is going to feel like pressure wise :/
I have not experienced this yet and I am 17.5 weeks on with my second child. But i have heard this is common, just for the reason you stated with your muscles and things being more streched then previously.