104 days late until yesterday

Miranda • i am 21 y/o, in a relationship, implied nude model

So I hadn't had a period in 104 days until yesterday. I was in a house hold where my ex bfs brothers gf got pregnant and once she found out she was pregnant my period starts to go away. I didn't know what was wrong with me. I didn't know if I was pregnant or not. But yesterday my bf (Israel) and his family got weirded out/excited because I was happy I had started my period. But it's weird because it's brown.... I pushed some kind of blood clot or something out yesterday thinking it was poop. I went to wipe and it was a brownish red but today it's just brown. I looked up why it could possibly be brown and 2 things popped. It could either 1. Since my period was late and I'm having brown bleeding it could be that my body was backed up and finally is getting the old blood out. Or it can be 2. And since yesterday was the day I was supposed to start my period in the first place, I could be pregnant. I'm hoping for the first because my bf just turned 18 and I'm 19 and we both aren't ready for kids yet. And we still live at his parents.

Has anyone ever had this happen before to someone they know your themselves?? Please I could use some support.