B.B.
First of all, congratulations! these type of things are so unexpected but are often the biggest blessings.
I'm SO not an advocate of the mini-pill. I also got pregnant while on it when my son was 5 months old, but i didn't know about it until I miscarried. My OBGYN told me I shouldn't ever take it again because obviously it wasn't effective and i'd probably just get pregnant again. So next time, look for alternative measures for birth-control, your doc can give you other ideas. not always as convenient as the (mini) pill but definitely effective. Best of luck!