Cramps on mini pill

Hi ladies! So I had my little guy 6 months ago and have been on the mini pill since my 6 week post partum check up. I've never missed the pill and have taken mainly with dinner. I'm also breastfeeding my little guy on demand. Well today I was out and about, no problems, then I came home and started cramping off and on. My period has not returned yet but is there a chance I could be pregnant or is this just a period starting back up? Thank you!