Question for those of you who experience vocal changes on The Pill

Will those of you who notice a difference in your singing voice when on birth control please describe the difference?

I have recently lost some ease of high notes and floats, and I frequently have a feeling of "thickness" that makes singing feel different. My teacher ruled out any technical causes for it, and a scope revealed no irritation from silent reflux. The only thing I can think of is that I recently began using the pill about 3 months ago. My voice almost feels like it sits a little lower. I become tired faster than I used to also.

Thoughts?