Could this be skin cancer?

Hello, basically I am concerned about a mole which I have had for a lot of years. It is roughly 5mm big and is raised. The problem I've got is it use to just have a uniform brown appearance. It was all one colour but within the last month or so it has started to become lumpy and rough with darker brown patches on it which seems to be spreading slowly across the mole. My mum originally pointed out that it seemed more raised. When I looked at it then it was slightly rough with maybe 2 or 3 very very tiny dark brown dots. Nothing too alarming at the time but I made a mental note to myself to keep an eye on it. Within 3 weeks or so it is a lot more.
I guess what it reminded me of was a strawberry with the darker brown spot things as the seeds.

I have very fair skin and unfortunatly do have a lot of moles. I do have an appointment with a dermatologist on the 18th but I just want to get a clearer idea as to whether it looks like skin cancer and if so what type?

Thank you