Spotting

I have pumped since my baby was born. I recently started slowing down on the pumping. I pump 4 times a day for 15 minutes right now and am trying to slowly wean down on pumping. I have not had a period yet. My husband and I want to have another baby and are not doing anything to prevent pregnancy. Tuesday and Wednesday I had pink spotting only when I wipe once each day....nothing today. I am wandering is that implantation bleeding ? I didn't have bleeding with my son . Curious if anyone did in their previous pregnancies or did you spot while breastfeeding?