Oooh, that "I" word gave me the creeps for a couple of months, trying to get pregnant, though I've been regular ever since. Doesn't mean that if a girl is irregular then she's infertile though. A lot of factors I should say could be related to infertility. Cause could be not being able to ovulate. And don't forget the guys too. The difficulty of having a baby is due to low sperm count.