if I miss a dose of my pill will I become pregnant?

Mamatoruben • 💙💗💛💚
I'm going on the contraception pill for a whole month but then stopping.
If I have sex the day I stop.. will I become pregnant?
Because they say do not miss a dose.
Has anyone become pregnant straight away after stopping?
My period are 40 days normally.. but recently been 7 days late, and I don't know when I'm ovulating. I use opk also.