Can't believe I'm posting this but here we go

So my period is 1 day late. We have been so careful and only had sex once during my "fertile week". We used withdrawal. So no condom but pulled out.(ran out of condoms and I can't take birth control so it was an oops thing). I know what you will probably say but what is the likley hood that I'm pregnant?

My periods have been regular so I am thrown off my periods use to be irregular but have been regular for a year now so my nerves are a little like uh oh😅😆