Pregnancy IS sex with a pregnant woman.
The penis couldn't go in far enough, so it ejected spermatic fluid.
The fluid couldn't go in far enough, so individual sperm swam in further, up where the ova were.
The whole sperm couldn't get into an ovum, but the head could, and it provided its chromosomes.
At first, the male's chromosomes could only get in the ovum and transform it, but as the ovum was transformed, the embryo it became eventually implanted into the endometrial wall and, after making a placenta - using some of the woman's tissue as well as its own - it leaked copies of its own cells and also loose chromosomes into the woman's bloodstream.
You apparently want to pretend that the woman and man are not still doing it merely because the man has removed the digits and other appendages of his organism, but parts of the guy are still inside her. If that woman gave birth to your kid, you are always having sex with her.
The guy can't give her pleasure that way, of course; instead, he can only give her morning sickness, etc. So if he cares about her, he might want to have more digity/appendagy/caressy forms of sex with her to make her feel better after giving her bad feelings, and if he doesn't care about her, he might not.
Who's perverted?