So, it turns out that the withdrawal method is pretty much just as effective at preventing pregnancy as condoms.
“The best available estimates indicate that with “perfect use,” 4% of couples relying on withdrawal will become pregnant within a year, compared with 2% of couples relying on the male condom. More realistic estimates suggest that with “typical use,” 18% of couples relying on withdrawal will become pregnant within a year, compared with 17% of those using the male condom.”