if I was more pregnant than I thought, then I do not think I got pregnant the one time we did not use birth control. Should that matter to me? Since one of the things I have been beating myself up about is that I was not "responsible" it kind of does.
Apparently I am not alone in this situation.
Fifty-four percent of women who have abortions had used a contraceptive method (usually the condom or the pill) during the month they became pregnant. Among those women, 76% of pill users and 49% of condom users report having used their method inconsistently, while 13% of pill users and 14% of condom users report correct use.
Want to know how reliable your birth control is in practice (scroll down to 7 for a chart on ideal v actual failure rates)