Birth Control Pill Timing & Effectiveness - Safe Alternatives?

Question
Mr. Solberg,
 I normally take my birth control pills (Levora) at 12 noon. Tuesday I started a new job and was unable to take my pill until 1:30, wed. I took it at noon, and today at 1:30. My first question is whether or not I am at increased risk of pregnancy for missing the pill by an hour and half these couple of days? Also,I would really like to be able to take them later at night now becuase of my schedule. Can I just start taking them at night instead, or will this increase my chances of getting pregnant?
Thanks so much!
Kelli

Answer
Hi Kelli,
The pill is extremely effective when taken every day at the same time.  It is much less effective in general use because women don't tend to take it every day at the same time.  An hour and a half isn't off much, so I think you still have good protection.  Switching to later at night is a bigger change, and will increase your chance of pregnancy.  If possible, I'd wait until you start a new pack to take them later.  Another way to do it would be to start taking them at night now but use backup protection for 1 week.