hair dye

Catherine
so this is the second time i post this, but i figured i would since in 22weeks now...anyways ladies how safe is it to dye your hair during pregnancy ? i want to go back to my natural dark brown hair since its low maintenance but im scared of doing it...i asked my doctor a while back if it was okay and shes said NO ! but then i see alot of women dye their hair during pregnancy and it doesnt seem unsafe...any suggestions or advice ? should i or should i not do it ?