Thanks for the reply. We both understand that pulling out is not going to prevent pregnancy its just something we do.
Probably not implantation.... Just could be some cramping. Maybe too rough, or it could be from your regular cycle, getting your period soon, etc... Unless it persists very bad, or if other symptoms occur, I think you'll be fine
However, if that is something you are worried about, the pull out "method" is *not* a real method to prevent pregnancy. If your concern is to not get pregnant, then use protection each time.