First time mom here. i'm wondering if my menstrual cycle has changed after giving birth? i'm breastfeeding, no period, how to figure out my fertility?

Hard to say: One of the primary reasons you menstruate is the failure of a released egg to become fertilized and save the prepared chamber. Yet you don't have to ovulate to menstruate. Breastfeeding can interfere with ovulation, but is not a dependable form of birth control, since ovulation is still possible. Accept that you may be fertile unless you use protection.