Is it possible?

So I’m only 16 years old.. and I had unprotected sex on Christmas <a href="">Eve</a>. I don’t know what signs to be looking at if I was pregnant. I’m pretty sure I’m not I just wanna get a clear understanding... I don’t really know how my whole cycle works... all I know is the 5-7 days I bleed and that’s it.i felt kinda bloated today but could that possibly b my period? Help please!!