Only a pregnancy test can tell you if someone is pregnant or not. Period (no pun intended).
So, I suggest you go and get one ASAP, or that she go into a clinic and have one done there.
I also suggest that you both get STD and STI screens and that before you are sexually active again, you buy a supply of condoms AND set up a reliable method of birth control.
But get the test done first.
Editor and Founder, Scarleteen
My epitaph should read: "She worked herself into this ground."
-- Kay Bailey Hutchinson