Susan is correct. It depends on what type of pill you are taking.
If you take a COMBINED oral contraceptive pill, you have a 12 hour time window to take your pills before they begin to loose efficacy.
If you take a PROGESTIN-ONLY oral contraceptive pill, your window is only 3 hours.
If you don't know which type of pill you are taking, you can look it up online or just post on this forum and I'll give you an answer. I am guessing it is a combined pill since that's what most women take. In this case, you would have nothing to worry about. But, it's always a better idea to try to take them at the same time every day so you get in a good habit of ALWAYS taking them.