Why does this happen?..IB?

I started spot bleeding. It was real light. I could hardly recognize a color..When I had coughed a drop came out and it was bright red and I ran to the bathroom..i put a pad on just in case an my blood started changing to brown on my pad. There was also fresh blood and the blood that was on there for a little while. Im not supposed to start in 4 days. Im just hopeing..waiting is a struggle..Im wondering how you could tell if thats mentrual..will it automatically come out brown if you are?