Burning pain in back, hips, and legs?

Anyone experienced a burning sensation in their hips, lower back, and legs while pregnant? Ive been nearly crippled by the end of my work shifts. Ive only had three since it started but its been progressively worse every day. Im off tonight but im still experiencing it just from being up and moving around with the kids during the day. It becomes MUCH worse if i take a small break to relax and get back up, the sciatic nerve pain will kick in if i do that. Its getting to the point where im having trouble doing simple tasks without my back, hips, and thighs feeling a burn like ive run 10 miles. I have an appointment with my OB on Tuesday, but i was wondering if anyones dealt with this? Its a pain and burning feeling all at once. I also had horrendous pain this morning from just above my right knee down to my mid calf that nearly had me calling my man home, luckily it went away after about 10 minutes.(it woke me up. Wasnt a charlie horse though) im on a double dose of baby aspirin to prevent against blood clots so i dont want to jump to that right away.