Just to complicate matters....
A friend's young teenage daughter didn't know she was pregnant, and it didn't show at all. Then one evening she went to the loo, and produced....a baby!!!! All happened rather quickly too, I gathered, though my friend was somewhat hysterical just afterwards and didn't explain it very well. But apparently the doctor at the hospital where they subsequently went said it wasn't all that an unusual situation, particularly with very young girls.
I just dread to think of that happening in a light aircraft!!!!!!