Birth control, ovulating, pregnant?

ok this is the situation my doc gave me provera to get my period to start and gave yasmin birth control to take after my period. i was told that depending on the birth control it can take a month to be effective. So before all of this i would have my period every 4-6 months so i wasn't ovulating the way im suppose too. Since i took provera i wont be ovulating for a month or two thou i had a period. Now ive started the birth control process to regulate my periods but i was wondering if i would stop taking the birth control would i go back to being irregular and not ovulating??? i would like to start getting ready to get pregnant after-wards...so thanks anything will help!!