Is She?

It certainly is possible that your girlfriend is pregnant because even though you didn't ejaculate inside her, there are more than enough of the little swimmers in pre-cum to impregnate someone. It only takes one sperm, after all.

As for the symptoms your gf is exhibiting, I think it's a little early for the morning sickness to kick in since she's not missed her period yet but that's just from my experience.

You can get some preg tests that can be used earlier than the period is due but they are only about 50% accurate so it would be wise to wait until she is actually late before testing in my opinion, just in case you get a false negative.

If your gf is not pregnant then please use condoms in future so you don't end up either dealing with a baby or the aftermath of an abortion.