It can be remarkably easy to hide. My mom knows someone who found out her daughter was pregnant when she went into labor. (Apparently, the warning signs are baggy clothing and not looking her father in the eye.)
It's good to know Nagato exists in this universe, and what a doozy of a first line is. My only hang-up with the strip might be that Mikuru wouldn't be that assertive about this stuff, but I can let a lot slide from the Kandachi canon. We might never get a third season of the show proper - or heck, not even new light novels - but for as long as the original MOHS canon keeps inviting talented individuals to come up with their own situations, I will happily read those and be thankful that such a rich source of inspiration exists.
I also love that baby Nagato is almost always frowning. Anyone who has worked with babies for a living - such as yours truly - knows 9 babies out of 10 are exactly like this.
*Brief tangent into American superhero comics*
'Nagato births a child in an attempt to understand motherly instincts' is delicious Silver Age lunacy, up there with 'Superman fakes two people's deaths to teach Jimmy Olsen a lesson' and 'Lois Lane becomes a black woman for a day to learn about racism', and I applaud it. That kind of anything-goes drive should appear more in the media - not only comics - that used to entertain us in our younger years. And it is what makes BATMAN '66 currently the best Batman comic - and one of the finest comics, period - being made now. Read it.
*Tangent over*
Asahina-san?! Why are you giving me that look?!W... Who's the father?!This is the result of a phantom pregnancy.I did not have sexual intercourse.No... I don't think so.Data Has Been IntegratedIn an attempt to understand maternal instincts, I have birthed a child.So it's imagined, then...I would like to request your cooperation in the upbringing.