First: yes, it is possible for her to get pregnant that way.
Second: it's most likely .W.A.Y too early for a pregnancy test to give an accurate result. When is her period due? There are some early-detection tests, but it is generally a good idea to wait until the period is missed. She can also get a blood test done, which can detect the hormone pregnancy earlier, but i'm not sure how much earlier.
Third: what do you mean "she's feeling wired?" i'm assuming you meant "wierd," but that still doesnt' tell us anything. Even if she .I.S pregnant, at this stage, she's probably imagining symptoms.
The only thing you can do is wait until her period is missed and test again. And/or go to a doctor.
Also, wear a condom and/or have her get on birth control if you plan on having sex or anything like it.