Reading between the lines I'd say that A would have communicated to C that her period was late (N says this was by text but who knows?) and therefore pregnancy was possible.
I'd also hazard a guess that as she was on holiday abroad with her parents at the time it could have been difficult for her to have bought a pregnancy test.
What is a little odd to me is that it was confirmed by a doctor, I wasn't aware that doctors still did that, it's not the 1950s anymore, no one in my experience nowadays expects a doctor to confirm the result of a home test
JMO
From a comment on one of the previous pages here that is assigned to N, I think maybe A was a few days or a week late plus maybe she had started getting morning sickness or other signs?
I think the doc's confirmation is what N has been using to say "A didn't 'know' until after C went missing". In other words, A had an idea but the doctor's confirmation didn't come until after. So N isn't telling an outright lie, but she's not telling the full story either.
Heavy stress can mess with regularity, A might have just wanted the extra confirmation from a doctor, she might have medical reasons for wanting to see a doctor for confirmation rather than relying on a home test and not seeing a doctor until she was further along. I don't think things like that are things that need to have question marks assigned to them.
I don't think C's private life or depression or anything had much to do with what happened. I see the bin as being the most likely way out of the horseshoe. I think the contribution from his private life is likely more about the heavy drinking, his way of being able to go out for a night and spend a lot of the time doing his own thing, and things like that, so that there's more chance of a bad drunken decision not having mates around to keep an eye out, and then a tragedy ensues, a river, a bin...
N's been between a rock and a hard place with C's private life and SM accounts. And ever since the beginning N's been all over the place in the theories in her head and what she pushes out to the media. Abduction, homicide, a feeling that maybe someone isn't telling all they know that turns in the media to "N says someone's covering up for homicide!" and things like that. Of course her mind is all over the place, of course there are places her mind doesn't want to go, all of this is totally natural, and we shouldn't let her police-like professional persona keep us from realising that and having sympathy for her on that level. She has no body, she has no certainty, she still has so many questions, so many what-ifs.
This was a missing person's inquiry, not a soap story. IMHO the police have gone above and beyond with the amount of resources dedicated to this case for so long. I'm glad and grateful for that. It's so easy to look back from the outside and say that maybe they could have done some things differently, but they have done a lot of work for Corrie, and if that was enough to guarantee finding him, then I am sure he would have been found within a week. But it isn't always enough.
