"Yeah, I think if it was appendicitis, you'd be totally nauseous and in pain for days"
Not entirely true. I had appendicitis a couple of years ago and it only felt like cramps. I thought it was gastroentiritis, but the cramps remained constant. After a few days, I went to the doctor thinking I would get a prescription and that would be it, but after an exam, he sent me to the emergency room where it was discovered my appendix had already burst and I was rushed to surgery. The doctors were baffled because the pain was not intense and I had no fever or nausea. In fact, I was really hungry and wanted a cheeseburger. I had to get a full appendectomy and it took months to fully recover.
Now, if the pain is really in your side and feels almost like broken ribs, hurting when you breath, it could be pleurisy, which can be easily cured with antibiotics. But abdominal pain could be anything ranging from indigestion to parasites to hepatitis, so it should should not go unchecked. I don't want to sound fatalist, but if it lasts more than a day getting it checked out could only be beneficial. If it's nothing, then you can relax. If it's serious, they can catch it before it gets worse.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian