No period! Help! "I'm not pregnant"

Kitty • Living with PCOS. Mom of two boys 👦🏻Jayden💙👶Ethan💙 🤰🏻Logan💙 wanted a princess, but got three prince instead 🤷🏻‍♀️ hoping to adopt in another year or two!
So i had my son about 3 months ago. I had my period at 8 weeks postpartum which only lasted a little less than a week. My son turns 4 months on the 20th of this month. I haven't gotten a "regular" period yet. I have pcos but I've never missed more than a month so I'm confused. I googled that women who exclusively breast feed sometimes get lighter periods or no periods at all but I only pump, and it's not much daily either. Would pumping be the same as exclusively breast feeding? Has this happened to anyone else
And no I am not pregnant, I'm a single mother of two and I haven't had sex since last year August aka I was already pregnant at the time.