FUE hair transplant, a lot of oil coming out of my skin. I had oily skin issues but not that significant. Is it normal?

It has been 4 days since my FUE hair transplant(2600 grafts) but from the 2nd day oil started coming out of my hairs.forehead.I had sebum before the transplant and oil used to come out from my head but now the quantity of the oil has increased significantly. My doctor advised me to shampoo twice with normal saline water which is I'm doing but after 2 hours of using the shampoo the oil starts coming out again and so I'm getting worried that if it would effect my transplanted hairs or is it normal