The chances are slim. Having it on upside down means that any sperm came in contact with the spermicide. Precum also contains minimal sperm if at all unless you masturbated recently without urinating after that.

How did you get the condom on upside down? You can not roll it down when upside down?

Of course you know that she can not get pregnant every day of her menstrual cycle. Only a few days around her ovulation. So depending on where she was in her cycle she might have been infertile any way.

Emergency contraception (Plan B) is for just these circumstances. In future it would be wise to use a fresh condom when something like this happens or emergency contraception if you find out too late to change condoms (for example when a condom breaks).

it was not completely upside down, only slightly unrolled in the wrong direction, before i caught it and reversed it. Thanks for your input, too!

RESOLVED! she started her period today, were in the clear i believe.