Low. That is what birth control is for, to prevent pregnancy. It amazes me that so many people take birth control pills and don't trust them. If you take your pill at the same time every day (within 3 hours), then you are protected. The chances of pregnancy are somewhere in the 1-2% range.
If you continue to be concerned, make him wear a condom again. I advocate condoms anyway, due to the overwhelming amount of sexually transmitted diseases.
The time you take your birth control is whatever is best for you. I like to take it at night when I go to bed. My best friend takes it in the morning before she brushes her teeth. Whenever you will remember it is the best time for you.