My girlfriend is having lower Back Pain really bad. She says is on the opposite side of her belly button. She just started birth control this month and her period started yesterday. She thinks it may be dehydration? What could be causing this? She’s also having pain with deep breaths.
Its really bad. She says it hurts to turn.

sounds like normal period pains to me. i get Lower Back Pain when i’m on it. where is the pain with deep breaths?