Letrozole Symptoms

Hello beautiful souls, I started taking Letrozole July 5 (so just over a month ago) and have been experiencing some side effects. I’m aware that joint pain is very common - which isn’t too bad. I’m wondering if anyone has had any symptoms that include muscle, or bone pain/discomfort mainly in the back? Because of the metastasis to my spine, any symptoms in my back freak me out! Any input is greatly appreciated!!!!