Why is it so hard to get pregnant during breastfeeding even though i got my period?

Irregular cycle?: Most women who are breast feeding regularly have irregular cycles because they are not ovulating each month. Without ovulating you can't get pregnant.

No ovulation: When women are breastfeeding her body makes a hormone called prolactin that suppresses ovulation and in some menstruation.That is why you dont get pregnant even if you have normal periods, but no ovulation. Some breastfeeding mothers do not get their periods and that is called lactational amenorrhea, means no periods due to lactation, and no ovulation as well.