Spotting should I be worried?

I’ve been spotting for 8 days now and I’m worried my doctor isn’t worried yet because of it being light. But I’m still worried. It ranges from a tint of pink to a brown color. It couldn’t be a miscarriage if it’s not bright red right? And it hasn’t been more then spotting hopefully it stops soon my ultrasound is March 22 so in six days. Should I be worried even tho it’s not blood red ? Also I have a yeast infection and bacterial vaginosis could that cause spotting?