Shorter period than normal?

Well I had PMS for a week and I was supposed to start my period this Monday (the 18th of September). It didn't come but I was up most of the night of the 19th being a worrisome person and anxiety is a normal thing for me before my period. So I go to the bathroom to pee and I wiped and there was the peachy stuff you get right before your period starts. So I started panicking more because I thought I was pregnant so when I bled a little more and I knew it was my period. That's when I started crying over it?? Then I bled throughout the day and today (the 20th) I bled some more and now I'm not bleeding as much so me being the worry wort that I am, I think I'm pregnant. I'd like for someone to let me know if this is normal and I will answer any questions that need clarifying