I have been on yasmin birth control for 7 years and have recently stopped and for the past 3 months I have not had a period?

you have been on birth control for along time. Your body really needs to have time to get it's natural clock back. I have heard people going upto a year with no period after stopping birth control. If you have stopped to get pregnant beaware that it could take a long time to concevie. Your body has been fooled and needs time to get back on track