Mind Over Matter

I was examined by my obstetrician yesterday. He told me he's sure the baby will be born next week.

"What!" I cried. "Not next week. No. no. no. Not before the 31st, please."

This is not part of my plan. I have things to do next week. I have a dentist's appointment, for heaven's sake.

My doctor just smiled smugly, all of his 40 years of medical experience packed into that one confident smile.
"We'll see..." he told me.

So now the question is simply: can the mind triumph over matter??