The Night I Got Pregnant by the CEO

Shiori works at the same online apparel company as her boyfriend, Keiichi. But on the day of their 3rd anniversary, she discovers that he's been cheating on her. Heartbroken, she goes to drown her sorrows and ends up passing out at a bar. The man she meets takes her back to a hotel to rest, but as he tries to leave, Shiori pulls him back. Moved by his sincerity, she asks him to spend the night with her. She thought she'd never see him again, but in a cruel twist of fate, he has become their company's new CEO! Moreover, Shiori discovers she's pregnant with his child?!

(Source: MangaPlaza)