I have a mole on my leg which I saw a (private) dermatologist about around 18 months ago. At the time, they said it needed to be monitored and recommended I get it looked at again in 6 months time. If I'm honest, life got in the way and I pretty much forgot about it. 
 

fast forward to 3 weeks ago, I realise that it's changed quite considerably. It's basically a completely different shape now. I felt like an idiot for not getting it looked at sooner and immediately rang the GP. I sent a comparison of what it looks like now vs 18 months ago and he agreed it had changed quite a bit and immediately said he'd refer me urgently to dermatology. 
 

today I got a letter saying my referral was being reviewed, and to call the hospital if I've not been contacted by the 6th of October (which is a good 7 weeks away). I'm a bit confused because urgent referrals are meant to take 2 weeks, and now I'll have to spend the next 2 months worrying about this and not knowing if/ when they'll contact me. 
 

does anyone happen to know why they could be reviewing it? Is it possible that the hospital has been the photos I sent to the GP and don't think it's urgent? 
 

any advice / reassurance would be very much appreciated, I'm starting to get pretty anxious