How do you know if you have an ovarian cyst?

Lonely Star

I’m wondering because it never fails, every month I’ll get sharp pain in my side. Apparently it’s due to ovulation... but honestly I don’t know. Because ovulation pain is only supposed to be for a day, but mine last for a week and sometimes longer. I seriously have to deal with cramps 2 times in one month. It’s awful. Sometimes I even think I have endometriosis due to my bad period cramps . Any other ladies in my boat?