Days after my expected monthly period i noticed i bleed just a few dark brown blood and it stopped i had cramps and tender breast lack appetite ?

Unlikely pregnancy: It's unlikely to be a pregnancy if you had the bleed, or it could be a blighted ovum. If your breasts are larger, more tender and you are having classic signs of pregnancy it would be good to do a pregnancy test. Otherwise it's safe to wait and see if more obvious signs of pregnancy are present. I don't suspect this is a pregnancy based on what you have said.