that sounds either like implantation bleeding, if it occoured before your period was due, or bleeding around the time your period is due is due to there not being enough preg hormone to stop a small period like bleed but enough to keep the pregnancy viable. Some women have a bleed like this every month when their period is due, they mistake this for their periods and dont find out they are preg until aroun12 or so weeks, it may have been abit to early for you to have a pos result, test agin using first morning urine, and dont use the digital test as it isnt as sensitive as the dye ones
Did you turn out to be pregnant?
Same thing happened to me wait another week or two and take another