What is this book?

I saw a promo post for this, but the information on the post was wrong and I can’t find the post in my history.

But they said it was a BL omegaverse story.

The top has white hair, pretended to be a pregnant omega, he is actually an alpha.

The actual omega has black hair, and the promo book cover had the two of them and a child.

I know this isn’t much to go on but if anyone has an idea, please let me know!