Should I buy plan b?

I’ve been on bc pills for over 4 years now. I’m really good at taking them on time, however last night I didn’t. I was out with my friends and totally forgot my pill. I ended up taking it 4 hours later that night. I ended up having sex TWICE that night as well after I took the pill. He pulled out both times but part of me is just so anxious. It was the last pill of the FIRST week of the pack. I’ve been reading things online and some of them are confusing. Some are saying to use a back up method, take plan b, and that I’m totally fine and protected. I took ALL the other pills of the pack on time. Should I be okay??