When do you get your period on the pill?

You should get your first period after beginning your birth control pills when you start taking the inactive pills (the green pills in some packs) or within taking a couple of the inactive pills.

Since you are just starting out, you may be experiencing breakthrough bleeding, in which you have some vaginal bleeding at odd times that only lasts for less than a day and isn't necessarily all that heavy in comparison to your regular period. You will also experience breakthrough bleeding if you miss one too many pills in the pack.

If you miss your period on your first set of inactive pills, it would be wise to seek a pregnancy test. If it is negative, and you miss your next period on your second set of inactive pills, you should seek the advice of the prescribing doctor. It's possible that you could have a condition, one being endometriOSis. From experience, Birth Control pills had no effect on the regularity of my cycles whatsoever. But this isn't likely for you, just a possibility, and a point to showing how necessary it is to speak with your doctor.