Confused

I’m only 19 so I’m not in meno pause

Periods getting shorter every year

2020

Had normal 7 day periods

2021

I had 7 day periods sometimes I would have 5 or 6 days once or twice that year.

2022

Last 7 day period was January 2022

Since February 2022 I’ve been having 5 day periods

Then June 2022 I had a 4 day period

Then July it went back to 5 day periods every month

and now…

November 29th to December 1st (I had a 3 day period)

Today December 2nd is more like/so spotting then a period honestly

Can Anyone can explain?

But now that I say that about December 2nd I now have an update 11:40am

This just happened not sure if it’s blood clot or not but I was spotting and then stopping and then spotting then stopping every hour off and on until now at 11:40am now I’m bleeding heavy and….had what looks like a clot?? Not sure