Supernatural/fantasy pregnancies have really been stuck in my brain lately, so I'm gonna write my train of thoughts on that.
I love a good fantasy story, full of magic and whimsy and escapism from the normalcy of life. You know what makes it even better? BIG FUCKIN' TUMMY!
An alchemist, down on their luck, decides the smartest thing to do is get knocked up by a magical creature for potion ingredients. Turns out that dragon jizz makes for a really good stamina potion. Luckily, they've got a constant supply of it now. And a belly full of eggs, which their new dragon mate loves to nuzzle and lick.
Elves and Dwarves live for a heck of a long time. Consequently, their pregnancies also last a while. Shortstack Dwarves flaunt their baby-filled bellies for several years, growing steadily as they prepare for birth. Elves, graceful and lithe, are stuck waddling with a heavy bump for even longer. Yet they wear outfits that show off their tummies, worshipped for being fertile and healthy.
A succubus gets summoned and makes a deal with some wizard that wants power. So she births him an army, turning into a baby machine. They end up falling in love and raise their kids together, getting into domestic hijinks. There's barely any moments where the demon's tummy is flat anymore, since they're pact-bound to breed almost nonstop. Good thing magic makes life a lot easier for a woman who has big demon babies, always kicking and making her hormones rampant.
A werewolf pregnancy where the carrier can get by on most days. But when the full moon is out, their belly goes from normal-sized to looking ready to burst with triplets. The baby gets more rambunctious, wriggling like it wants out. The parent-to-be also gets cravings for dark meats and carbs aplenty, lending to the child's excessive growth. Hopefully, they give birth before the next full moon.
A fertility deity chooses a mortal champion, unwittingly impregnating them. The newfound divine-chosen being is shocked to immaculately find themself pregnant. They always wanted a child, so it's no problem. It's only a problem when they keep making babies. The attention to their condition has earned them a holy status, where they're worshipped fervently. Foot rubs, oils for their always-taut bump, fresh fruits to snack on, gorgeous clothes that tailor their growing body.
A shape-shifter/Changeling gets knocked up and thinks they can just turn into a male to avoid having a big bump to carry around. Turns out it doesn't work that way. They get a lot of stares when they get stuck like that for a while. It's especially challenging when they go into labor without the proper equipment to push out their baby.
A dungeon has had a bad reputation, but the treasure within is worth the danger. Except that treasure is cursed to make the person who takes it give birth until they've had as many babies as the value of its horde. One unlucky adventurer finds out too late and their belly suddenly surges forward as they instantly go into labor. The pregnancies are rapidly occurring in succession, and they churn out spawn after spawn, as the value of the treasure was thousands of gold.
Goblins are starting to dwindle in population, so they end up having a large breeding season to offset their losses. Some travelers come across a tribe who are particularly prolific. They've been given a pass to document the situation, observing several goblins carrying hefty litters that kick constantly. They might even get invited to some orgies if they play nice.
...Maybe I am a weird nerd. I could talk about this stuff for a while.
If anyone has other fun ideas, I'd love to hear them.