HELPPP!! Question about pill effectiveness!!!

Ch

So girls on the progesterone only pill, you should know about the one that you can take up to 12 hours late. Well I need help!!

I took the pill at around 11am on Sunday, then forgot to take it on Monday morning and had unprotected sex at around 3pm Monday, I then took the pill when I got home at 9pm, was I covered as it was within the 12 hours ?? Or do I need plan b!!