I took plan b as a precaution

I took plan b as a precaution because there was a slim chance something went wrong. I took it this morning and everything went well, tonight I had some diarrhea which I’m guessing is the result of my body cleansing itself out? I personally don’t think I needed to take it. It’s just that my boyfriend and i had a small hiccup, and there was a small chance some semen got near/in my vagina by accident despite not having penetrative/vaginal sex. I feel better already and other than this the side effects weren’t even really apparent. I’m just wondering if anyone knows if this is how your body releases all of the stuff you put into it when it doesn’t need it.