In this story beta are like the people in our world. Beta man can't get pregnant.
It depends, it’s up to the author
The author said Beta men in this story can’t get pregnant, a while ago on twitter
Omegaverse world doesn't have certain rules, since it's like that in some mangas they can but as far as I know in this manga they can't. ┗( T﹏T )┛
In the Q&A she responds some questions about betas
http://www.mangago.zone/read-manga/love_is_an_illusion/uu/love_is_an_illusion-chapter-43.5
that ^
also, in most omegaverse manga's i've read betas are usually the "more closer to what a human is" among the three genders. and not able to be pregnant is included.
Uhh... can anyone plzzzzz tell me if a beta can get pregnant or not? caz I've read some where a beta also can get pregnant♀