Will plan b work ?

Okay I know this isn’t smart but apparently I’m ovulating this week and tomorrow is my chance but I don’t want to get pregnant but if I do it’s just meant which me and my husband do not mind but I don’t really want to have another child so we decided to get a plan b and I’m taking it today will it be effective right away ? As I am ovulating . Any advice or answers ! From experience?

When should I try taking a 7 day before pregnancy test I would be getting my period on the 1st and I had unprotected sex while ovulating wasn’t aware until I checked but I took a plan B and was told it wouldn’t work so now I’m waiting to see what happens but I was curious on when to take a clear blue test ?? Any suggestions?