I appreciate your query.
Since you have been taking birth control pills regularly, chances of your conceiving immediately if you stop pills is slim
Also, chances of pregnancy
are more if you miss the pill and have unprotected sex around your days of ovulation ( normally day 14 if you have a 28 day cycle - the unsafe days are 3 days before and 3 days after ovulation ).
If you want to conceive, stop birth control pills after finishing the current pack.
Wait for your next period, take adequate pre conceptional counselling
and then plan your pregnancy systematically.
Return to fertility
sometimes takes a few months in case of pills, however that is not always the case , and you might get pregnant earlier.
All the best.