How long after hair transplant to have laser removal?

I had a hair transplant and there are some white hairs on the front line of my forehead. It is about two months after the hair transplant, and every week I see even more, what can be the reason? I noticed my forehead became very small after the hair transplant, the doctor said to use hair laser removal 3 months after the hair transplant. Now is it possible to remove them by laser or there is any alternative or solution?