28 weeks sharp pain

My stomach constantly feels like I have pulled muscles it hurts when I cough and sneeze it hurts when I roll over in bed and when I stand up from sitting down it takes me a minute to be able to stand up all the way and stretch my stomach muscles out, also when I first stand up and I take a step with my right leg I get a wicked bad pain in my lower back/ but area. I have a doctors appointment Thursday   I just wanted to see if anyone else knows what it is, thanks in advance!