I Had A Miscarriage On May 10th. My Miscarriage Was

I had a miscarriage on May 10th. My miscarriage was complete and all signs of pregnancy left my body. On June 13th I got what I believed to be my first period since having the miscarriage. It lasted 3 days. I am still nursing so that is normal for me. I now am showing signs for my body of being pregnant again. I've been dizzy had headaches and have the dark line growing up my stomach. Could I be pregnant? What about the period I had?