Should I take a plan b?

I have 31-33 day cycles and I have gotten pregnant first try with both kids so I’m worried that I have a high chance of pregnancy. Anyways my period is due in 9 days and my husband didn’t pull out in enough time. I ovulate around CD 16-17 which has already passed. Should I still take one? I know they only work if you haven’t ovulated yet so since I’m passed my ovulation window should I still take one or would it be pointless?