Thank you Clysta, 20% or lower is very reassuring.
It's hard to say what your exact odds would be. Because you only just started your BC, it hasn't had a time to be fully effective. Without knowing when you ovulate, it could be either or. IF you were ovulating, you would have a 20% of pregnancy - this is the same for any couple trying to conceive. You also carry this risk if you ovulate within the next 5 days, as sperm can last that long inside the body. If you weren't ovulating and will not in the next few days, you have no risk as there's nothing there to get you pregnant. You can take a pregnancy test two weeks after you last had sex. Make sure to use first morning urine for the best results.