Love is an illusion I think
do omegaverses have different world building? Yeah, different authors make different rules. I like it that way though.
Different authors build their omegaverse differently. But for this one, I am sure there was a bit of time leap in that last AU chapter since Yiho can talk and walk now. I am sure Yirim was pregnant for ~8 months(they specified the weeks when Yirim gave birth to Yiho) in the actual story, so maybe it was the same for the AU.
This is the first time I've ever seen an omega get pregnant twice in just one chapter. Anyway, do omegaverses have different world building? I swear I saw somewhere say that omegas only get pregnant for a few months and not actually 9 months. I think it was Blood Link? I don't remember.