Period already

Has anyone got there period after just 4 weeks post partum? I had an emergency c section and I'm formula feeding. After 3 weeks my bleeding turned to brown spotting then just 2 days before 4 weeks I started cramping and bleeding bright red again and it feels just like a period. I'm also on the birth control patch. I called the doctors and they said it sounded like my period and it was normal. Anyone else ever get it this early??