will the plan b work?

hi guys, i just got off my period 2 days ago (eve said i have low fertility) and me and my bf had unprotected sex, he pulled out on time but i just took a contraceptive the same day to be safe. i want to know if it will work at the time i took it in my cycle, which was 2 days after i got off my last period. any info helps besides the question i have ! thank you i hope my post helps others as well!