inconsistent vaginal fluid

i’m worried because my menstruation was one month and one week late and suspected that i’m pregnant but the time i had my menstruation i had a relief. after 1 week, I’m worried because there’s a black vaginal discharge that is coming out in my vaginal and I’m scared that maybe i got miscarriage during my last menstruation. i’m scared pls i need advice and tips also information about this. for the info i already took a test but it was negative so i’m confuse now. thank you