Period lighter than usual?

So I started my period on the expected time I was supposed to get it. I had cramps, everything was bright red and I passed a few blood clots but it wasn't as heavy as it usually was on my second day. It was heavy yea, but not to the point where I needed to change my pad every 3 hours. Is it normal to change flows randomly sometimes. Any feedback would be great. I'm freaking out. ):