A 2% per incident risk will add up to a yearly 50% risk for the average user.*
I think the figure you’re looking for is 1 - (0.98^100) = 0.87 (assuming no-one gets pregnant twice in the same year).
I think the figure you’re looking for is 1 - (0.98^100) = 0.87 (assuming no-one gets pregnant twice in the same year).