Is this appendicitis or other thing?

Is this appendicitis? Or what?Yesterday afternoon I felt a very terrible pain in my lower right abdomen... I thought it was my ovary and it stopped after 30 minutes. At night the pain appeared again and I wasn't able to walk, but the pain again dissapeared. Today I woke up early and I felt stomach ache but I hasn't any pain in my right abdomen. The pain appeared again at 5 p.m but it is almost invisible. I dont know what to do. I called my mom and she said It was just my ovary and that it shouldnt worry me. I know an appendicitis should be treated inmediately but my mom dont believes me, because when i was younger I felt a similar pain and was just my right ovary ovulating. Btw i am 15 and im in the middle of my menstrual cycle. I also feel some pain in my right