So Nervous! Please help!

Ok so I am 6 days late. I took a test on Sunday and it was negative. I took another on Wednesday and it was a faint positive. My chest is very sensitive but I've also had cramps. They aren't like my cycle cramps though. I was going to wait to take another test this coming Monday to see if it's a more difinitive yes, but sorry if this is TMI I went to the bathroom and saw a little brown discoloration. What is going on? Could I just be that late, or is it a miscarriage, or normal? When I have my cycle my chest is never sensitive. What are your thoughts! Please help!