You are probably right. I just noticed a pattern, but I am not the best person to ask about this stuff. I just don't know. I thought perhaps it was post nasal drip because I have gotten that and tonsil stones at the same time.
However, not all breath odor is equal. It's just as generic as someone saying "b.o" - what kind? Haha. I hope you find a solution. I new a girl with breath odor (a good friend, actually) that said doctors found too much protein in her urine. I never followed up with her about this, but I always thought it could be why her breath smelled after she told me.
I noticed her breath was not the typical bad breath, it was more mild, but still strong to me because it had a bit of a strange odor. I cannot remember it well enough to describe it, unfortunately.
I will add that absolutely NO one reacted to it. It wasn't obvious and you had to be right next to her to smell it.