C.D.
Hi C.! I got pregnant with my third child when I was breastfeeding an 11 month old. Take a pregnancy test to check, get a multi pack so you can check it in a week if the first one comes back negative.
But it also could be just a light period from this being your first period and your body is just trying to get back to normal. Either way, I would go ahead and take a pregnancy test just to be sure. Best wishes, and good luck!