I said this already in a reply below, but whatever. The reason why Hyesung can't easily get pregnant is because he is a RECESSIVE OMEGA. It is in the nature of recessive omegas that their fertility is low. That is the version in this omegaverse. NOT because he is a male, or he is a late bloomer or whatsoever. He's recessive, that's all. Recessive omegas and alphas in this omegaverse have lower abilities, in terms of mental and physical (and apparently that includes impregnation and conception), compared to their dominant peers. And I also mentioned this, but I think it's because the first 5 or so chapters in here are poorly translated that's why a lot of people are confused. If you want to fully enjoy the story, go read the official release, or if you can't afford, read the version here: https://mangadex.org/manga/23544/love-is-an-illusion which is pretty accurate.
I said this already in a reply below, but whatever. The reason why Hyesung can't easily get pregnant is because he is a RECESSIVE OMEGA. It is in the nature of recessive omegas that their fertility is low. That is the version in this omegaverse. NOT because he is a male, or he is a late bloomer or whatsoever. He's recessive, that's all. Recessive omegas and alphas in this omegaverse have lower abilities, in terms of mental and physical (and apparently that includes impregnation and conception), compared to their dominant peers. And I also mentioned this, but I think it's because the first 5 or so chapters in here are poorly translated that's why a lot of people are confused. If you want to fully enjoy the story, go read the official release, or if you can't afford, read the version here: https://mangadex.org/manga/23544/love-is-an-illusion which is pretty accurate.