Last month i finally got my period after being 7 months postpartum.. and I am 2 days late on my…

Last month i finally got my period after being 7 months postpartum.. and I am 2 days late on my period... but I really don’t know if it’s going to be regular or irregular due to the fact that I’m still breastfeeding.. I have noticed some nipple soreness.. I don’t remember feeling that before my periods, I’ve had breast tenderness in the past for my periods but not just nipple soreness.. this has only happened with my last pregnancy so I’m wondering if it’s my period or could I possibly be pregnant?