I had the mirena (levonorgestrel) taken out in october and started taking mircogestin 1/20 and last month i didn't have a period and i also breastfeed my son?

Missed Periods: There are several reasons you have mentioned that could be cause of your missed period. First you had a switch in birth control methods and therefore had a change in hormones. Outside hormones alter your internal production of your own hormones which may take up to 1-2 months or more to regulate your cycle. Breast feeding also alters your hormones, adding yet another component to missed periods.