i am also about 15 weeks and I have a ton of pain on my sides, it is called round ligament pain. my dr. told me as long as your not bleeding or throwing up you are fine. so try not to worry and take it easy i know it is hard. I also ice my sides for short periods of time and lay on my side and that helps, I understand though i can't even stand up sometimes it is painful! try not to sit a lot and lean forward that seams to bring on my pain even more. good luck and you should be fine, but if you bleed or start throwing up due to the pain call your dr. asap!
Check with your doctor to ease your mind, but as Chel125 said- unless you start bleeding or throwing up due to the pain, you should be fine!
check with you doctor but i agree with Chel, sounds like round ligaments pains, which can be pretty painful. i get mine mroe when i go from a sitting to standing position.