I askeda nurse about this, because sometimes if I get up too fast, I feel like I've pulled a muscle in my uterus or something. She said something about a "round ligament" and that your uterus is growing, so it hurts to stretch it..it's normal.
I got this from the "**********" site.
"What is round ligament pain?
It's generally a brief, sharp, stabbing pain or a longer-lasting dull ache that women commonly feel in the lower abdomen or groin, starting in the second trimester of pregnancy. You may feel it as a short jabbing sensation if you suddenly change position, such as when you're getting up from a bed or chair or when you cough, roll over in bed, or get out of the bathtub. Or you may feel it as a dull ache after a particularly active day, say when you've been walking a lot or doing some other physical activity.
The round ligaments support your uterus in your pelvis. As your uterus grows during pregnancy, the ligaments stretch and thicken to accommodate and support it. These changes can occasionally cause you pain on one or both sides of your abdomen. You may feel the pain starting from deep inside your groin, moving upward and outward on either side to the top of your pelvis (where your hips are). The pain is internal, but if you were to trace it on your skin, it would follow the bikini line on a very high-cut bathing suit."