Q: When can I get pregnant and when should we have sex after the pill?

A: As soon as you stop the pill it's safe getting pregnant. It could take between 2 weeks and several months after stopping the pill for ovulation and your fertiity  to return. You might want to have sex regularly, once a day or every other day or so, around the time you think you might be ovulating or when the ovulation-prediction kit shows you are about to ovulate, just to make sure you don't miss the important day of ovulation.
It's also suggested in general to make love regularly two to three times a week throughout your cycle, for the very same reason, as you never know exactly when ovulation will happen.