What the heck is going on!?

Troy • 23 years old
Hi everyone so this month I have had the weirdest period first things first I'm not on any bc or anything like that! This month my period was due on the first and it didn't end up coming till the 5th well wen it did come it was super light some days even just spotted and Mostly brown. It lasted till the 11th which is very unusual for me. Then on the 14th I went to the bathroom only to find the it was back on again and once again it's spotted to really light and brown. I've already taken 2 pregnancy test one after I missed my period and one a few days after it started! They were both negative so i really don't kno what's going on with my body..anybody else kno!?