Bf and his mother...

I met his mother the same time I met him, and knew right then and there that, while it wasn't a dislike, she didnt approve of me. But he did so we went on. Yet, to make him happy, I still kept in touch with her and today was no different. I called her. When she knew it was me, she hesitated. But I still asked how she was. She said "oh so so." That didnt sound right so I asked if she was alright. She said "I rather not discuss it." I respected her wishes, we hung up.
But here's the thing: though she didn't approve of her son and I, she always, and I'm talking about ALWAYS told me of her health. This time she didn't and of course that raised a red flag.
Some of you may have read my previous post concerning his lack of communication which is making me wild. So now I'm thinking this may be the cause as in perhaps something is going on between mother and son that has her upset? Of course I don't know. So quite naturally you guys don't know either.
But I am asking your opinion. Please?