You have at minimum 12 hours to take a pill on combined pill, usually it’s 24. So a 4 hour time change doesn’t make a difference.
Assuming you’ve been using it correctly and accounting for anything that can interfere with the pill’s effectiveness, you’re fully protected by the pill.
It’s not unprotected sex, pregnancy wise, it’s condomless sex as the pill is your protection.
If you ever have any doubts you’re best to use condoms, not worth the stress of worrying about it!