Count your cycle from the first day of your period, until the first day of your next period. That will make it easiest to determine how long your cycles are. My cycles changed drastically after my second child. Whereas before, both on AND off the pill, I was 28 days like clockwork. Then all of a sudden, inexplicably, I was suddenly having cycles that ranged from 25-34 days. Now that I have recorded them, I can tell that my cycles go in waves...25 the first month, then they gradually increase, then for a couple of months it was stay at 28 days, then it will increase to about 32 days, then it will start again at 25 days. It's totally weird, but our bodies and our cycles change as get older (I am only 29), and of course, as we have children. Try recording your cycles, both now, and after you've started again once you've had your next child.
I know this it totally weird, but good luck to you!