Take plan b

Ok.. please don’t judge me! And no rude comments! I’m 6 weeks postpartum and my husband and I had sex last night for the first time.. we didn’t use protection, I’m not on birth control and he DID pull out! I also got my first period at 5 weeks postpartum and it ended the day before we did it! Im in no way trying to get pregnant again and yes I know! Use protection! But it just kinda happened.. he’s in the process of Getting a vasectomy.. his appointment is next week! So my question is… do you think I should take plan B today just In case or is it a very low chance because my period ended the day before?