Formula of pregnancy inflation (story) 2.0First are you sure you want to write such kind story, even if it will be really bad? Of course you are, without bad ones there would be good ones.More Like This
So let's begin. Find a way to write story down. Paper fits, but if you want to upload it to dA you need better way, my suggestion would be MS office word or other such style programme but they are better for fixing grammar mistakes, if you want something more mobile you can use mobile for this. How ? I hear you asking, well write story as email and send it either to you account on PC or copy paste to enter text part while submitting. I use this way over three years now and still use it to write stories (even this one).
Now you have on what and with what to write let's begin. In story you need three main things: way of impregnation, "victim" and place.
Start with way. Popular ideas are alien, magic and science, other ways are not showing what caused impregnation, rape (sometimes done by werewolf), plants and mix of those above.