Period after 3 month deliver. is it okay?

Assalamualaikum. Baby sy baru 3 bulan 2 minggu. Sy full bf tp dah start period. Darah boleh kata quite banyak macam period before pregnant. Masa baby 2 month ++ ada period jugak but sikit sgt. Now during period, kpala asyik rasa sakit and berat and kerap rasa nak pitam. My first question Is it okay for a full bf mom period this early? Second : if it's okay, adakah all the side effects is normal?