take your fingers and poke towards the lower right side of your abdomen. if you feel a sharp pain, i would not wait until tomorrow. i would definately go to the ER and get it checked out.
i woke up 4am and went straight to WebMD and did the checks like it told me. however, i still was confused so i went to work anyway. at work, i felt feverish and nauseated all morning, so i asked my boss if i could go to the doctors during lunch time. went to the doctor, he poked my stomach the same way i did at home, and i felt a sharp pain.
he immediately registered me for the ER and the next morning, i had the operation done. worst goddamn pain in my life when i woke up (could not move, which could have proven useful because i had to pee like a horse after the surgery), and i felt groggy for a month afterwards.
not trying to scare you, but it is not very good if it burst inside. it can cause serious infections.
when was your last bowel movement, and was it hard? this is when i knew something was wrong, because my crap was hard like a brick, with red material in there.