I agree with deteragram-- One or two hours makes no difference at ALL. Kariva is a COMBINED oral contraceptive pill. This means that you basically have a 12 hour time window to take it. PROGESTIN-ONLY pills have a much smaller window; only 3 hours before protection becomes compromised.
Most information encourages one to take their pills at the same time every day so one gets into a good habit of ALWAYS taking it. It's a good practice, because missing a pill can have some bad repercussions. But, if you take your pill at 6 pm every day, you could take it at 6 am at the very latest and not expect any compromised protection. Of course, it's really better to take it at the same time
If you are taking your pill as consistently as it sounds, there is really no need for condoms. The pill alone, if taken every day, is more than 99% effective. Can't get much better than that.