So long as you're taking your pills generally within a 4 hour before and after time period, things are generally okay. I'm not going to say more than that, because other factors affect how quickly the pill is metabolized other than time.
Just a suggestion... there are other forms of birth control that do not require you remembering to take a pill everyday...
Depo-provera: one shot every 3 months, protects you for 12 weeks. Most people stop having their periods on this medication.
Nuva-Ring: vaginal ring about the size of your thumb and first inger made into a circle. It is flexible and the hormones are absorbed through the vaginal walls. Most don't feel it, it can fall out during sex, and can only be out of the body for 2 hours before risk of pregnancy occurs.
Ortho-Evra: patch that you wear for a week at a time. Has been known to fall off, cause skin irritation, and morning sickness.
Of course, every method has its pros and cons, and if you would be more confident using one of these types of birth control, please see your physician.