Morning after pill?

Hi all, I've been on the depo injection for 2 two years and about 5 months ago I started taking the pill (cerazette). I came off this pill last Monday and haven't had a period yet. We had sex this evening and the condom came off inside me so it's safe to say it was very much unprotected sex. Should I be getting the morning after pill or am I worrying about nothing? I'd appreciate any help :)