Well, you got carried away, I guess. Never wise to insert your penis unprotected into a vagina or anus. It was unprotected? Good news though, it was so brief. With full penetration for the normal amount of time, risk of HIV is less than one percent if the other person had hiv. (zero if they didn't). While I would think that the less than one percent chance of hiv would make you feel much better, you still should test. You would want to take a 4th generation DUO test at 28 days or beyond. It will most certainly be negative but you want to confirm it with a test taken at that time (do not take one earlier). Other std's are honestly also less of a concern with a few seconds of penetration. I would not be overly worried. If you are going to a clinic, you can get appropriate guidelines for what to test for.
I'd not go back to this person. What she did was irresponsible given her profession. That's not the kind of person you want to have this type of activity with as you want them to always be safe. (you too, by the way. make good choices).
This will likely result in anything more than a wake up call for you to be more careful.