It's very unlikely she's pregnant, but having sex without a condom is very risky business, Tris. You can take an inexpensive pregnancy test 14 days after this behavior to put your mind at ease.
Don't worry I don't think she's pregnant. How long exactly has it been since you had sex? Why don't you tell her to get the morning after pill (some are effective for up to 3 days after unprotected sex like the Plan B and others can be effective for up to 5 days like the EllaOne but of course, the sooner you take it the better). Just to bare in mind that taking contraceptive pills can mess up with her menstrual cycle ( when I took the EllaOne, I got my first period, got brown discharge for the second month until I eventually started getting getting my third period) good luck!