Spotting....

So I've been nursing and pumping for 12 months. Last month, June 17, I got my first period. I am still nursing once in the morning and pumping 3 times while at work, during the day. July 7, I started spotting. I thought maybe it was implantation blood. But I've been spotting every day since the 7th. I took a pregnancy test (two tests actually) and they're negative. I'm really confused. Is this my period? Do I need to wait a little longer and maybe I'll get a positive pregnancy test? Or is it normal to spot while breastfeeding?