I started my period reg on September 1st had sex on the 17th and bled for 1 day a week later and my reg period is now 2 days late.

Could be pregnant. It is in the realm of possibilities. Though you're going to need to wait until next Wednesday to test. Two days late isn't really late. The best time to test is about two weeks after you should have started your period. That will give you the best chance of testing positive if you are pregnant. Make sure to use the first urine of the day. Good luck!

Periods are late, are early and sometimes are missed. So while , yes of course you could be no way to tell yet.

You can try a pregnancy test now. But false negative is more possible this early.

So test, first thing in the morning, as soon as you wake up.
If negative wait two week and test again