Thank you very much! It actually came out last night! I'm so relieved :)
If your period was supposed to start soon, then it's probably just your period. The abdominal pain may be from the lost condom that could have caused problems or may just be normal menstrual cramps, it's hard to guess. Normally, your body will expel anything that isn't supposed to be in there on it's own naturally. Although if you can't find the condom and it doesn't come out of you within a weeks time, you may want to make a doctor's appointment to make sure it's not far up in you. If it gets left there for too long it may cause an infection or other problems. Hope it all goes well for you.