I wanted to mention Elogium and the problems with airing it as part of Season 2, as well as the problems it causes as-produced.
Elogium doesn't really match up with normal Human female gestation - especially once you throw Fury into the mix (I'll get to that in a bit) - but it's far less problematic if it's restored to its proper place in Season 1, where it follows Projections (in which The Doctor indicates that it's been 6 months since the events of Caretaker). It is
possible for women to not realize they're pregnant until they actually go into labor, and some of the reasons for this phenomenon occurring are stress, a lack of typical pregnancy-related side effects, and/or the baby being 'inactive', and I can very much see any or all of these things having happened to Ensign Wildman, which would explain why she didn't find out she was pregnant - or really 'show' - until she was 6 months along.
Stardates notwithstanding, I can also very easily see Deadlock taking place within 3 months of Elogium, which would actually do away with the apparent problems with Sam Wildman's gestation entirely.
As for Fury, I don't see anything in that episode that precludes its events from constituting a different timeline where Wildman's pregnancy was in fact doubled because of the baby's Ktarian genes.
I personally think Fury causes more problems than it fixes, and would therefore be inclined to think of Wildman's pregnancy actually being fairly normal and one or a combination of the 'outside factors' I mentioned above being the explanation for why she only learned she was pregnant 6 months into said pregnancy, but to each their own.