Period or something else?

Update on my Plan B issue. So I took plan b on the 13 which is also the day that unprotected sex happened. I don’t know if he got off (he probably didn’t? Idk I can’t feel it either way 😅😅 sorry for the TMI) but it was first thing in the morning so I assume there was precum. Now I know there is a very slim chance of getting pregnant with that. Anyway I digress. Since I took plan b my breasts have been sore I haven’t started my period yet. I know it can make your period late and Cause sore breasts so I’m guessing its just side effects. I’ll probably still take a test next week if I don’t start 🤦🏼‍♀️