Hi @Jrcn - I too have had joint pain with both Letrozole and Exemestane (been on it for about 5 months now) - but mainly in my hands/thumb just now. I often wake up during the night in pain.
Sadly, joint pain is quite common with a lot of the hormone tablets. Mine has lessened in the last couple of weeks - but was badly affected on the weekend when I was fishing & got caught out in a big storm.
Have you had a bone scan at all since your diagnosis? If you haven't, It might be worth mentioning this to both your GP and your Onc ..... any unexplained pain for longer than a few weeks/month or so - should really get checked out.
My mantra is "IF IN DOUBT, GET CHECKED OUT''
All the best xx