I admit I was very reluctant to read mpreg. My scientific brain can obviously accept paranormal stuff but it has a very hard time wrapping itself around the idea of a male being pregnant. The actual how and why is glossed over here so you do have to suspend belief because there is no rational explanation… however, once you do that, the story was absolutely wonderful.
As mentioned by others, there is no sex in this and like some others, I agree that it wasn't missed (well.... of course it would have been much appreciated.) What you do have is the MC's personalities perfectly depicted to a "T". Derek is his usual taciturn, grumpy self but also possessive, protective and sooo in love with Stiles. Stiles too is his typical impulsive self but his strengths really do shine and he comes into his own with perhaps a new twist that he's more than just a human among wolves.
For those too who might scoff at this due to the lack of smex and the fact that they're already an established couple - don't. There are nuances to their already evolved relationship and their feelings toward each other change and strengthen in this story. It does play out month by month but it's more than a play by play of the pregnancy; there's even a baddie arc interspersed in there.
As per my usual disclaimer because this is fanfic, your love of Teen Wolf will enhance the read - but if you're not a fan, it shouldn't detract at all. Really - not at all. And those flashbacks at the end??!! Swoon!!
Rosa thank you for the rec; I don't think I can read any more mpreg because it won't be as perfect as this.