When is the right time to stop contraceptive pills to prepare for conception, and how long would take for me to conceive?

At end of pill pack: How long have you been on ocps? To avoid irregular bleeding, i would finish your pack and then if ready to get pregnant, do not start the new pack. How long it will take to get pregnant is very variable - you could get pregnant next month or take 1year. On avg it takes ~6 months if on pills for >2 yrs.

Conception: Stop the pill (ocp) when you are ready to conceive. Avoid alcohol and other substances that could be harmful to a fetus. Start taking prenatal vitamins. You can get pregnant in the 2-3 days prior to ovulation. During the fertile time you might notice increased clear vaginal discharge that is stretchy & slippery. Sex 2-3 times a week and daily just before ovulation will typically work!