My girlfriend has not had a "real" period in over 10months, she's not on the pill, and she's 100% not pregnant. She was recently given medication for "hidradenitis suppurativa" which the disease can cause period problems. She's been on her period for over 2 weeks, it's heavy and she's worried. Does anyone know what can cause it? or if it's just her body becoming regular again after fighting the disease. She's been on the medication (anti biotic) for about a week.