Nijiiro no Cinderella

from fictiondb:
He wants his baby, so he'll make her his bride!
To teacher Erin Lavelle, handsome billionaire Peter Ramsey was like a fairy-tale prince. But after two amazing days their affair was over. Peter had thought Erin was different until he discovered her secret.
Then seven months later he finds her pregnant. Now there's only one way to ensure his unborn child's security...marriage. Erin's knight in shining armor has returned, this time demanding she be his bride!