Help?!

I’m an EBF mom & ive been on the mini pill, 4 weeks PP. Only recently (1st week of March) did I notice a strange pattern in my “period”?! I would only bleed for 3 days & it would end. But not heavy enough to bleed on a pad, so I’d use just a panty liner & everything’s fine. Although I am getting the menstrual cramps, Would you consider this an actual period or just spotting from the birth control? And should I be worried about being pregnant?