Have you taken Plan B before? Need some insight!!

My boyfriend and I had (or at least tried) to have sex a little over a month ago. He was having trouble getting himself up and had some mishaps with the condoms. We still decided to grind on each other for the feel of it. He didn’t ejaculate but he did produce a lot of pre-cum fluids. He knows that pre-cum doesn’t produce sperm but sperm can leak into the fluids so he wanted me to take a Plan B just to be on the safe side.

Last month my period was about a day late. This month I am two days late into what would be my “normal” cycle. I know my chances of being pregnant are low, but I was wondering what y’all’s experiences were with Plan B? Did it change your cycle for a few months? Did you experience any side effects?