Ages ago, I read an article in the Guardian written about clinical errors when transferring or creating embryos.
Of course, this planted the idea in my head that the clinics we used could have mixed up our eggs, sperm or embryos, particularly as we had to cart embryos between clinics (that is a very long story, and it was a very odd day).
So, I think more than most new parents, I seize on any suggestion that the Boy looks, or doesn't look like, my husband or I.
"He's getting ginger hair! You've got a ginge!" said my brother in law. There's only one member of my family who had ginger hair, an alcoholic uncle who died estranged from everyone else. Which at least reminds me that genetics aren't everything.
But then -
"He looks so like your husband in that photo." said one of my friends. Phew.
My father in law has confused the issue by insisting to us that the Boy has similar ears to his mother, and then telling my husband's sister that actually, his ears are nothing like his granny's. For some reason, the ears are of particular interest to my father in law. Even though even I can see nothing remarkable about the Boy's ears.
Ultimately, it is all really silly - I don't honestly believe that the Boy is not ours. People see what they want to see. No-one from one side of the family says he looks like anyone from the other, they all see themselves or someone closely related to them.
Babies look like babies. I did warn the midwife that if he came out a different colour then there probably had been some mistake somewhere along the line. But, even if he had come out bright green with purple polka dots, I don't think I would have complained!