Could I possibly be pregnant again? 6w pp

KK

I am currently 6 weeks postpartum. I stopped bleeding about 2 weeks ago. Today I noticed when I wiped a couple times I was bleeding just a little. It has stopped since. I have had unprotected sex a few times but my dh pulled out each time. I know it’s not a reliable for if bc. I am also exclusively breastfeeding. Do you think that bleeding was implantation bleeding or just some pp bleeding?