Could I possibly be pregnant?

It sounds like it's okay.
But, you don't need any more panic situations like that. Maybe next time, if you end up having sex without birth control of any kind, consider equipping yourself with the morning after pill.
But of course it's better to use the BC pill or condom.

At that time you don't really know if your pregnant you at least have to wait a month to know if your pregnant that's if your period has not came and maybe what happened t you is that you probably had sex to close when your period was going to come that it skip days for it come I that's what happened

If you had your period then you are not pregnant. You can have late periods. You should learn to calculate when you are ovulating so you don't get pregnant. With some women the day you start your period is when you count the days. So first day - the 10th day your find its after that use protection. A week before you start your period you are fine. Like I said it's better to be safe then sorry. Use birth control or a condom. If you are irregular there is no way to calculate when you ovulate. If you are that worried go take a test.

You can't be pregnant because it doesn't matter if you came on your period late, but you still came on.

Don't worry I'm pregnant because I took these 3 cheap (well 1 dollar pregnancy test) and it all came out positive---

Actually you can still have your period while you are pregnant. It does happen sometimes, but usually it is a little lighter than normal. Women can actually get pregnant at any point in their cycle, they are just most fertile at the time of ovulation. It is even possible to get pregnant at the time of your period. You need to read up on some sex education information, preferably from a medical website. If your period was any lighter than normal, you should get checked out.

I don't think that you are prego because you did get your monthly so there shouldnt be no worries.