If it has a heart at four weeks, then they can't say it DOESN'T have one at 9 weeks, which is what he was saying. Not that the heart starts off beating (Which it does by the way, it's just really faint since the child is only 1/25 of an inch at the time.) That is, of course, unless it takes a vacation and just walks off between the 5th and 9th weeks. (I wasn't going to note my sarcasm, but since people seem not to be able to tell that I am being sarcastic, I'll spell it out anyway; The walking off part was sarcasm.)