Breastfeeding & delayed period?

I finally got my period last month of almost a year of nothing probably due to breastfeeding my son. QUESTION THOUGH! I'm late this month.. only by 1-2 days, but all pregnancy tests have been stork white negative. We did have sex during my "ovulation window" but we used the pull out method so there was a small amount of contraception used. Just wondering if breastfeeding could delay your period again after it returning? I'm never late and everytime i am i'm pregnant lol. My last pregnancy I didn't get a bfp till 13-14dpo I believe.. but it ended in miscarriage unfortunately. With my boys I got dark lines around 10dpo. So confused😖