Louisa's Pregnancy
I've been a long-time Doc Martin viewer and recently decided to do a re-watch. I've just started Season 4, but there are things about Louisa getting pregnant that leave me puzzled.
One, Martin is almost obnoxiously concerned with Louisa's state of health, and he certainly knows all about the biology of how babies are conceived; yet, he had sex with Louisa apparently without contraception in place. Two, having had sex without contraception, Martin would certainly have been aware that pregnancy was a possible outcome and that Louisa could potentially have been pregnant. In fact, it would have been in character for him to have said something to that effect, but he never does.
It seems to me like a point in the show where the plot needs for things to happen a certain way, so they do.