You can get pregnant anytime near your period, although it's harder at some times than others. Usually a woman is the most fertile during the 14 days before her period starts, but it varies. Birth control usually doesn't delay becoming pregnant.
Some pills have side effects which deserve a bit of looking into.
None can make you barren, however, so I doubt you have anything to worry about. Im not sure if stopping the pill influences if youd menstruate the first month or not. If you're showing any signs, and your period comes lighter than normal, take a test. You can get pregnant anytime near your period, although it's harder at some times than others. Usually a woman is the most fertile during the 14 days before her period starts, but it varies.