Oooh, that's a possibility. I have major problems with my pelvis and hips going out all the time in pregnancy. Visit the chiropractor if you can. I always go every few weeks in my last trimester. I totally need it!
Eeek! That could be many things and painful things shouldn't be taken lightly. check out this http://www.ucsfhealth.org/conditions/pelvic_pain/signs_and_symptoms.html
You should make a doctors appointment to stay on the safe side.
It almost feels asthough I shifted my pelvis bones
Sometimes when you move a little too fast or too much you will get those pains like a runners stitch. In your sides....if it was like that then it's more the fact that you strained your ligaments a little. I did that when trying to go for a walk through a trail my last pregnancy. I was walking all the time but one day it really hit me. I had to turn back around and walk back when I hardly even started!
I would call your doctor. It can be a number of things. You will want to get on to of it if its anything serious so it doesn't affect you through out your pregnancy. I don't think it could be anything to hurt the baby but will just cause you problems. don't stress on it. Your doctor will let you know what's best to do.