Statistically, the odds of transmission ...

from an infected male to an un-infected female are something around 14% PER YEAR of sexual activity if all that is done is to avoid risky contact when symptoms are observed. Adding a condom, depending on whether the symptomatic regions are covered by the condom, is a good step in reducing risk, but is never 100% effective.

The thing about statistics, by their nature, is that they only apply to a statistical group and can never predict the outcome of individual cases.

In your case, how long after the activity was it before you noticed the symptoms? Often sexual activity can trigger a later outbreak due to minor trauma to the skin, stress, etc. In general, it is thought that OBs *after* sex are not too likely to be a big problem in relationship to transmission.

The only real way to know is for your partner to get a good type-specific IgG blood test at least 12 weeks after possible exposure. Of course, that alone doesn't mean that she didn't already have herpes. A baseline test right away is a good idea.

You did tell her about your having herpes beforehand, didn't you?

Let me know if I can help further.