I've been experiencing sharp pains in the left side of the abdomen, about 4 cm from the navel (to the left) for about 2-3 days. I feel it when I stand up and take deep breaths, sometimes when I'm walking or stretching while standing up too. I don't feel it when I lay down. It doesn't hurt when I press the area while laying down. The type of pain is very similar to the pain one sometimes feels in the right side of the abdomen after running, for example.