Weird period

So my period this month has been a little strange. The first two days I barely bled at all. The next three days were super heavy. Then I assumed it was over because my period only really lasts five days. But the last three days since I finished my period, I’ve been spotting. This has never happened to me and I took a pregnancy test to make sure I wasn’t pregnant (I’m not). I don’t know what could be going on and it’s starting to worry me. Unfortunately I was laid off work recently and do not have money or insurance to go to a doctor. Can anyone tell me an idea why this is happening? (24years old. No kids).