What are the chances? Am I okay?

Even though he pulled out you can still get pregnant from pre cum as it sometimes contains live sperm which can survive in the woman's body for up to 7 days.

Did you think about the morning after pill?

Being stressed can make your period late, or mean you miss one altogether.

I would suggest, you speak to an adult you trust. I would recommend your parents, tell them you might be pregnant, BE HONEST about everthing. They'll appreciate you going to them, they'll be a bit mad and disappointed but then it's expected as they want the best for their children. Your mum can get a Home pregnancy test kit which you need to wee on first thing in the morning before you drink anything as this is when your urine is most concentrated.

Repeat the test in 7 days after taking the first one to confirm the results or confirm a pregnancy.

I really do suggest you be honest with your parents or just your mum if you are pregnant, you are going to need their support during the pregnancy, and for ante natal appointments.