I had forehead reduction/hairline lowering, I'm beginning to get indentation on my forehead, is this permanent? (Photos)

I had forehead reduction / hairline lowering 3 weeks ago and last week I began to develop indentation from the middle of my hairline down to my right eyebrow. I contacted my surgeon who told me not to worry and it's probably just how I slept last night, but after a week it's not going away!! What can I do to get rid of it? And why is it occurring? Thankyou (please ignore the pimple right in the middle of in the indentation).