Mpreg Magic is an amazing thing and MPREG in the Potterverse is a beneficiary. It can bring two men closer together or possibly drive them apart.
Alliekatgal •It Could Only Happen to You, PG, 738 words. Read review here. Warnings: (highlight for spoilers) *Mpreg* Summary:Severus attempts to dispel the notion that Harry could become pregnant. After all, that could never happen. Ever. Really.
Anya Elizabeth •The Beauty of Childbirth, PG, 726 words. Warnings: (highlight for spoilers) *Mpreg, childbirth* Summary:The birth of Harry and Severus's first child. In which Severus remains cynical to the end.
Asnowyowl •The Tie That Binds (Chan, 16-18), NC-17, 12,966 words. Content/Warnings: Chan (highlight for spoilers) *Chan, 16-18, Hogwarts Years, Mpreg, Rimming* Summary:An affair between Harry and Severus holds unexpected consequences and dangers.
Bk7brokemybrain •The Blessing, PG-13, 2,650 words. Warnings: (highlight for spoilers) *Mpreg* Summary:Harry and Snape pay a visit to Privet Drive to beg a favor of Aunt Petunia. Oh, dear...
Curia Regis •Behind These Fortress Walls, NC-17, 8,000 words. Warnings: (highlight for spoilers) *Non-con, slave!fic, mpreg* Summary:The invention of a male pregnancy potion allows the wizarding world to rebuild after the devastating war.
Empathic Siren •At the Heart of Things, NC-17, 12,256 words. Warnings: (highlight for spoilers) *Infidelity, miscarriage, non-Snarry pairing, angst* Summary:After being forced to bond five years ago, domestic tranquility does not reign in the Potter-Snape household. Severus thinks he's found something better, only to realize everything he's lost. He decides to prove himself to Harry one day at a time.
Faire Weather •Entre Nous, R, 4,260 words. Warnings: (Chan - Harry is 17)(highlight for spoilers) *Chan, incest, mpreg* Summary:Severus is cold, and nothing is helping.
Gingertart •Nine Days Wonder, NC-17, 8,100 words. Warnings: (highlight for spoilers) *Mpreg, crack, sex magic, and drastic over-eating.* Summary:AU in which Dumbledore died from the curse before Draco could attempt to kill him, the trio didn't run off on a camping trip, Ron makes good on his early promise of being a brilliant strategist and Snape gets his usual shit deal from fate. He does get heroically shagged, though.
Janice Lester •Expecto..., PG-13, 10,200 words. Warnings: (highlight for spoilers) *Mpreg, EWE, pre-slash.* Summary:Snape gets a visit from the stork stag. Harry gets an unwanted house-guest.
Kai •A Necessary Evil, NC-17, 53,595 words. Warnings: (highlight for spoilers) *Character Death, Dark, Mpreg, Horror, Suspense* Summary:After the Final Battle, Albus is pregnant (!) and Lord Voldemort is almost-dead yet again.
Klynie •Love, Pregnancy and Camel Riding, NC-17, 27,600 words. Warnings: (highlight for spoilers) *Mpreg; awkward sex between two middle-aged wizards.* Summary:48-year-old Harry Potter is the victim of an accidental immaculate conception.
Lexin •A Life More Ordinary, R, 24,465 words. Warnings: (highlight for spoilers) *Mpreg, angst, AU* Summary:Snape is told some bad news, and it goes downhill from there.
Lexin and Tidmag •Unnatural, NC-17, 27,514 words. Warnings: (Chan)(highlight for spoilers) *Mpreg, hermaphrodite!Harry, chan, AU* Summary:Far far away, in an alternate universe, hermaphrodite Harry gets into trouble. That's not just ordinary trouble, but "trouble".
LoupGarou1750 •Great Liars, Great Magicians, R, 24,000 words. Warnings: (Chan, 15/16) (highlight for spoilers) *chan (15-16), mpreg (faked), BDSM, cross-dressing, humiliation, toe-licking, AU, humor, angst* Summary:Dumbledore forces Harry to bond with Snape, who demands an heir, but when Harry announces his pregnancy, Snape doesn't believe him. The road to hell may be paved with good intentions, but the path to love is strewn with sex, lies, and manipulations.
Mahaliem •OMG! Not Another MPREG!, M, 6,000 words. Read review here. Warnings: (highlight for spoilers) *Humor, mpreg* Summary:Harry and Snape fall in love, have a baby, and live happily ever after – NOT! (except for the baby part which is, unfortunately, true)
Ntamara •A Small Price to Pay, PG-13, 872 words. Warnings: (highlight for spoilers) *Mpreg, infidelity* Summary:They were going through a rough patch, nothing more. It wasn't serious. Harry was young, they'd been together for a few years now. Of course he'd become a little restless. That didn't mean he didn't love Severus anymore, that didn't mean he was actually going to leave.
Everything would be all right. They'd promised to be together, forever. Severus was not going to lose Harry to any of those opportunistic bastards that Harry called friends. Not if he had any say in the matter.
Occasusvenustas •Less Hate, PG-13, 4,227 words. Warnings: (highlight for spoilers) *Mpreg, AR* Summary:A one-off can have consequences in the wizarding world. Harry Potter finds that out the hard way.
Scheming Reader •(Thoughts of) Christmas in July, PG, 1,100 words. Warnings: (highlight for spoilers) *MPREG, mentions of vomiting and a man with a vagina and breasts, and soft-boiled eggs with toast soldiers, and other things that are too cute to really go with Snarry.* Summary:"Snape is pregnant, and Harry is convinced that they need to both find a religion to covert to, so that their child is brought up within some sort of community of faith. So, he goes shopping for a religion. Snape is . . sceptical of the entire process. Hilarity ensues." I don't know about hilarity, but Snape vomits, and I know there is a fannish audience for that.