I got my period on the day I was supposed to im very consistent, I was not late but the only difference is the first three days my blood was a heavy dark brown with dark red mixed into it. The fourth day looked like my regular period but than the next day it was back to brown. I'm just curious as if this is normal for females or if this is what people call implantation bleeding.. I did also call my nurse she said it could be old blood or it could be implantation bleeding, I did take a test and it came back negative... But this is still bothering me.