How long after you go off birth control pill should you have your period? How long should I wait before I go have it checked if it doesn't come?

One month. In general, women should menstruate about once per month. If you have been off the birth control pill for over a month and have not menstruated yet, you might consider visiting the doctor to see what's going on. You can also discuss with your doctor an alternate method of contraception if you are trying to avoid pregnancy. Wishing you'all the best.