I've had this my doctor said it is old blood, but to be safe ask your doctor. I'm having a yellow discharge my doctor said it was normal.
I'm in the same boat, i went to the bathroom wiped and saw a dark brown discharge i have to wait till tmrw 2g2 dr. Since its a holiday weekend
Have you had sex recently? That may have caused it.
How far a long are you? I think if it's dark you might want to call your doctor.