My wife and I used condoms for our birth control, but there were many many times we used the old Catholic withdrawl and she never got pregnant. Of course we did worry a little. Then when we wanted a child she got pregnant the first month, so it wasn't like she had trouble getting pregnant.
Worry but don't let it devour you. In our talks we have decided that we will assume it is my sperm that won the race to the egg. Don't ask don't tell kind of. Of course now neither of us have to worry about getting pregnant, me the vas, she the hyst.
What if there are medical complications down the road we would address them at that time if necessary.
Good luck and give each other a hug.