Do I have an ovarian cyst?

Hi, I m 18 and female, recently I have been having this on and off pain in the right side of my abdomen.. it s not appendicitis because I ve had this pain on and off throughout the last few months. This pain is pinching and my upper right thigh feels really sore because of it. I have an extremely irregular period, and I m worried this is an ovarian cyst, what should I do