Old blood strains

So my expected period is in six days and for a week now I’ve been getting old blood stains on my underwear and it’s not small and unnoticeable anymore. It looks like I took a dump pulled my panties up before wiping then decided to switch it around... I need help. My boyfriends has been giving me looks and I know he’s not going to say anything but it’s embarrassing. Why is there so much?!