No if she had a period then she isnt pregnant. But the most important thing is the penis never entered the vagina. Pregancy cant occur unless semen gets inside the vagina. You are safe. But if you do have intercourse make sure to use a condom....

We won't be doing that for a long, long time

Even if she had a very light period, she can't be pregnant?

Sometimes there is break through bleeding. Which is the result of the egg implanting itself in the uterus. This could result in light bleeding that is very very light pink. But you still would need semen in the vagina to result in pregnancy. Maybe I should ask you this?

Do you or she insert semen into her vagina?

If not then this light period is just a light period. If you are still doubtful then take a pregnancy test. But I think you are just stressing yourself out for no reason.

Okay, thank you so much Rosie. I can't thank you enough

Especially if your girlfriend is young, her period will likely be irregular and may be unusually light at times. But no, she is almost definitely not pregnant.

When you guys start getting more sexually active, think about birth control. Because the time will come where you do more than just dry humping, and you don't want to be even more worried than you are now, do you?