Pregnant AFTER plan B?

Has anyone ever found out they were pregnant even after taking plan B? I feel silly asking but I’m a little concerned. I had a baby 7 weeks ago, the night before my 6 week postpartum check up I couldn’t take being sexually frustrated anymore and ALMOST had sex, my boyfriend’s sperm got on the outside of my vagina so I took a plan b just in case but this week I’m feeling nauseous and tonight I started throwing up, I’ve also been extremely emotional for no reason. Maybe my hormones are trying to get back to normal. I have a doctors appointment Friday but I’m just curious if anyone’s ever actually been pregnant even after taking it?

*i haven’t had my period yet either