What is this bleeding? back on the pill?

ive just started back on the pill yasmin ive taken it before with no problems, i was having really heavy periods so decided to go back on the pill im now on day 7 and im having this brown kind of bleeding for the last 3-4 days my periods are usually 4-5 days long on or of the pill. ive been taking it correctly but im worried it could be a problem what with the heavy periods after years of light periods and now this brown sort of bleeding it looks like theres clots in it to.