Mutant Healing Ability???

I went with my wife, Monica, to the doctor yesterday. We have recently changed doctors and this was her first appointment with our new one. Monica has been sick for over a week. She was diagnosed with a sinus infection. The doctor was questioning whether or not Monica really has a sinus infection. She thought that she may have the flu instead. When I heard the doctor say this I said,

"I have been questioning the same thing. Sinus infections aren't supposed to be contagious but I caught whatever she had."

The doctor then said, "it must not be the flu either if you are already feeling better."

Now I wish I could have my next sentence back.

I said, "I like to think that I have a super mutant healing ability and that is why I'm over it."

Silence.

The doctor never responded. She ignored my joke and went on to take care of Monica. I can't blame her for not responding. How do you respond to that comment?

It was meant to be a joke. As soon as I said it I knew it wasn't that funny and I just came off as a complete comic book nerd. I hoped Monica didn't hear it. We didn't talk about the comment after the appointment. In fact she didn't mention my comment until later that night. She told a friend of ours what I said and the friend responded with...silence. I tried to explain that it was a joke, but it didn't make it any better. Alas, I may have a mutant healing ability but I can't take back bad jokes. Have you ever said something you wished you could take back?