Shinnyuu Shain no Omega desu ga, Senpai Alpha Kaizoushimasu!
Complete | Kondou asahi | 2019 released
Struggle
Complete | 김닌자 | 2000 released
About an omega who thought he was a beta getting with a dominant alpha who stuck up for him. The alpha reacts rather ignorantly to being told "pregnant" and thinks his beta has a wondering desire to an omega girl. He ends up telling the beta to abort the baby but what he doesn't know is it's his own child growing inside his 'beta' boyfriend.
Yagi to Ookami no Hatsujou Jijou