precum and birthcontrol chances of pregnancy

hello,
My and my girlfriend have been dating for about a year
recently she was put on birthcontrol to help her with her heavy peroids
after about a month of her being on, we decided to do a little fooling around
finally we had sex for our first time
I did not fully ejaculate inside of her but im worried about precum
what are the chances of her being pregnant if shes on birthcontrol?
how would the chances be affected if she missed taking a pill for a day
thank you

if shes on birth control and taking it correctly you probably could have gone all the way and been fine. its been a few years since I've done extensive study into reproduction (reading dozens of encyclopedias, medical books, surgeon notes, ect) but if i remember correctly the chances are around 1/200 or something like that.


"precum" aka cows fluid has a lower ratio of sperm/fluid than regular semen, and its a small amount nonetheless, so even if she wasn't on birth control theres a good chance she wouldn't be pregnant, but its always better to be safe than sorry

of course this was posted back in October last year, so I presume you've found out whether or not shes pregnant by now anyways.