Hi, For months I have been on Co-cynprindiol for acne

Patient: Hi, For months I have been on Co-cynprindiol for acne and It was working great and recently I was switched to a ‘lower risk’ Rigevidon however my acne came back and my skin was so bad. I then decided to come of Rigevidon 8 days into my cycle (10th may). I have had withdrawal bleeds and my skin is starting to get bad. I have since went back to my doctor and have been prescribed Co-cynprindol again however I’m not sure when I will be able to start the new pill since I am not sure when my period will start? Please help, thank you (I’m from the UK )

Doctor: