I have no clue whats happening.

So I'm 15w and 4d with second child and with my first I was lucky enough not to feel anything at all that had to deal with pain. But the second one is kicking my butt. I need advice or something I'm calling my on call if the pain doesn't let up. My lower back is in heavy pressure like there is a burse on it and someone is just pushing on it but it doesn't have the ouch touch. The pain in my lower abdomen is at a level 4 pain but its like someone is taking the bottom of my pelvis near my left and right hips and pulling it together.