Is it possible??

I had my baby girl 10 weeks ago and haven’t gotten my period yet. I’ve been on light birth control (because of breastfeeding) for a month but I definitely missed about 3 days throughout the month. My boyfriend and I just had sex for the first time and he came in me because we both forgot that The birth control hasn’t kicked in yet. I’m thinking about getting plan B tomorrow (if I’m able to take it while breastfeeding) but is it possible for me to get pregnant again even though I haven’t had my period since giving birth???