It's quite normal to feel pelvic pain during pregnancy, as your body goes thru big changes to adopt for child birth.
Not only you get pelvic pains, you can also get cramps in lower legs as a result of stress, lack of water or vitamin deficiency.
If the muscle pain that you are experiencing occurs on a regular basis even if you have tried this method or if there are symptoms like redness, swelling and bruising then you should consult your doctor immediately and go in for prescribed medications.