Tymlos and lower back pain?

After 6 weeks on Tymlos, I am just now experiencing lower back pain and stiffness, especially when I wake up in the morning and after sitting for a while. The pain goes away with ibuprofen. I will track my progress. So far the discomfort has been going on for five days. Has anyone experienced this side effect and if so, how long did it last? Thanks so much.