You got clicking around on AO3 or maybe tumblr, and now you're scarred for life. You're also asking, "What is mpreg?" The short answer--and the long answer--are here.
What Is Mpreg?
W
A Brief History of Mpreg
A
It's easy to think of mpreg as a kind of modern invention, related to scientific advance and scifi writers. As it turns out, it's probably a lot older.
OUT NOW! Get ready for high seas adventure with SAVED BY THE SELKIE!