Hi, last night I when I was taking a shower I suddenly got a sharp pain in my abdomen. I thought it was just gas so didn't think anything of it. But after a couple of mins it just got more painful and I was almost doubled over. I lay down on my side which helped and went to sleep. This morning when I woke up, the pain was gone but I have a pressure in my lower back, and lower abdomen mainly on my left side which doesn't seem to be getting relieved and it becomes stronger when sitting down. My stomach feels hard and also, there is a slight burning sensation in my lower abdomen only when I sit down. I am 24, no history of medical illness. What could this be?