last night around 6:30 i was laying on the couch and when i stood up i got a really painful feeling on the left side of my abdomen in line with belly button. it made me double over for a few seconds. it has been sore on and off ever since, especially when getting up or tensing stomach muscles. i think that i have read this is normal 'stretching and growing' pains but what can i do about the pain. it really hurts when i move it and when i am not moving it is still tender. also how long should it be lasting for, it has been all night.