I get the exact same thing ecept mine is on the left side. The OB told me its normal the muscles are stretching to accomodate the extra weight in your uterus. If you stand up or move too quickly they pull because they are not used to it and i know it hurts like hell sometimes. If you get bleeding along with it see your doctor but apparently the cramps and sharp muscle pains are normal.
Have a great day
Mel