I'm 26, upset stomach, can't eat, abdominal swelling, bloating, always feel full, irregular cycle, can this be ovarian cancer, not on bcp, never had sex?

Cancer unlikely . Typically ovarian cancer has no symptoms until they are very advanced. Your symptoms are nonspecific, an don't point towards a single diagnosis. Ask your doctor if you could have irritable bowel syndrome, or if a referral to a gastroenterologist is appropriate. They can also do a proper evaluation. Hope this helps!