Absent periods

Morgan

Okay so I had my first child in August of 2017. Everything went by so perfect. Then I go my first period since birth in October. Than again in February I have irregular periods. But that was my last one until today. It came back five months later. I’m not pregnantI’ve taken many tests all came out negative. Has this happened to anyone? I also breastfeed. Can that be a reason why such a late period?