late pill??

I am on the combo pill Nikki and I took my pill 4 hours late. I usually take it at 2:30pm but instead I took it at 6:30pm. I had unprotected sex last night and he came in me so am I still protected?? Also I know that sperm can live inside you for up to 5 days so will I be covered then as well if it is still alive? Do I need to take a plan b to be protected?

Also the back of my pill packet says if I miss 1 pill i’m fine and dont need to use a backup method, I just keep hearing horror stories about women who get pregnant on the pill. I tried looking all this up but I keep getting different answers. Any info on this would be greatly appreciated!