mine ruptured a couple of years ago. Kind of felt like I had bad gas all day. I don't remember specifically, but at some point, it let up. That's when it ruptured. Went back to doing what I was doing. Ate dinner and started to get that bloated/gassy feeling again. By bedtime, I was starting to feel some pain and by 1 AM, I was curled up in a fetal position it hurt so bad. By then, I told the wife that maybe I should go to the ER and see a doc. 'Course, she though - since I admitted I might need to see a doc - that I was about to die and off we went.
After poking and prodding - they wouldn't give me any pain meds at first - for a while, they gave me some demerol. then half hour later, when I still rated my pain at a 10 out of 10 they gave me more. half hour after that, the pain was still at about a 5... but I didn't care any more!
at 7 I went to the OR for an emergency explatory laprotomy. My pain was centered in my belly, not on the right side, so they weren't sure. Once they opened me up, they found a rupture and all that goes with it (I'll leave the gory details out). Doc said much longer and I probably would have had a massive infection; life threatening massive.
Oh yeah, and this was all 5 weeks before my wedding! Anyway, all went well and now I have a cool 4" scar beneath my belly button.
If you're not sure, see the doc. Simple blood count should tell.