You had absolutely normal periods for 9 months after shifting to different pills. That means this is not a hormonal
problem related to your pills.
At this age, whenever such unexpected heavy or prolonged bleeding occurs, it may point for some organic problem in your reproductory system, more often in uterus
or mouth of the uterus(cervix
Please do not take the things lightly. Report to your Gynaecologist. You may have to undergo certain investigations like ultrasonography
, study of the uterine lining etc.
If your bleeding is not associated with pain, the chances of tumour in the uterus are remote. However, your uterine lining needs to be studied thoroughly to rule out any abnormality or lesion like infection or cancer.
Your early visit to the Gynaecologist is solicited for.