Why aren't my eyes looking straight at me?

Hi all,
I am returning to the world of drawing, and have a question about facial expression. I drew a quick portrait of a girl based on a photo (sorry, I lost the link to the original photo. Darn.) and noticed that no matter how I drew the eyes, they always seemed to be looking off to the right. In the photo, she was looking straight at the camera, and I loved her intense eyes.
I tried several times to draw her eyes accurately and eventually gave up. I probably won't go back and fix it (the daydreamer look will just have to work this time) but I'd like to know if anyone could possibly guess what I was doing wrong.
Thanks, and please let me know if there's more info I can provide. I'll try to upload the drawing itself soon, but right now my scanner is stupid. I may just photograph it.
Noura

PS: I noticed that, in the photo and the drawing, her head is tilted. Is that what's confusing my eye? If so, what can I do to compensate next time?

It's really hard to give any solid advice on this without seeing the drawing. There are a million ways to adjust a drawing to achieve the desired 'following eyes' effect you're trying to accomplish, so without a visual reference we'll just be wildly guessing. That's not very efficient I'm afraid! :(