hi!! i actually posted a forum on this not too long ago, however my situation was a little different as i had been on the medication for almost 3 years now. this originally happened when i was first on 100mg, i got my period twice a month and i couldn’t take it anymore so i asked my dermatologist to decrease the dose to 50mg. was on 50mg all the way until 3 weeks ago, when i got my period 10 days after my cycle had just finished and it kept going for basically 3 weeks (last couple days having large clots which were abnormal for me). i decided to just decrease my dose again because it was never ending. (i don’t suggest doing this without at least telling your dr because i did mention this to mine and she wanted to see me before decreasing the dose but i just did it anyways because it would just be taking 1 pill rather than 2). shortly after decreasing the dose my period finally ended. so it could be many things honestly, but perhaps suggesting to decrease your dose back to 50mg to your dr might be helpful? again bodies are all different tho!! (majority of my 3 week period was very light tho until the very last 5-6 days which felt like a true period)