My Daughter (16 Years Old) Has Irregular Periods. She Recently

My daughter (16 years old) has irregular periods. She recently started taking birth control pills to help regulate her cycle. Started period 29 days ago and had a normal period. Taking birth control as prescribed and also Topiramate for migraines. Today she is having pain in left side of abdomen. Not sexually active. Some nausea. No diarrhea or vomiting.