Well, you might pick up an STI. Did she have any visible open sores where you licked? That would make it more likely.
The more serious infections, however, are not so evident, and require testing. And you will have to wait a little bit.
From Health Central:
If you have had unprotected sex and are worried about an STD or HIV, you should get tested 1 to 2 weeks after and again 90 days later. This is because different STDs are detected at different times: Chlamydia – anytime from 1 week to 3 weeks. Gonorrhea – anytime from 2 days to 30.
You can get tested at any clinic. In the United States, Planned Parenthood is the best all around location for help on sexual health.
Be responsible now: no unprotected sex with anyone until after your second test in 90 days, and then only with a monogamous partner.
And next time, practice safe sex.