22 wks and so much pain

Carolina
Any advice on what I can do about upper butt pain lower back pain. My really not that big but I'm starting to ach so bad. My crotch bone is killing me too. This is my second baby btw/ with my first (5yrs ago) I was in a lot of pain too but I wasn't as philysically fit then. I was in really good shape when I got pregnant with this one. Pls HELP.