****TMI**** What is this?

I’ve been on birth control for a week and two days now, and I started it on the first day of my period (which was recommended by the directions) and my period is usually only 6-7 days but it’s been 8-9 days. Do you think it’s because of the birth control? And I keep getting these, I’m guessing it’s just a little blood clot? I’m not sure though. Any help you give will be appreciated!