for people who have read the novel, is there mpreg?

yes!

Where did you find the novel pleasssse

If you make an account here (free) you can see & click on links for all three groups translating it.
https://www.novelupdates.com/series/diamond-dust/

All 3 groups use machine translation so kind of wonky, but novelib seems to be the best so far. https://novelib.com/story/diamond-dust/ it is a bit behind the manga, like about where ch 13 is. Borntonovel is mid-story wise and Oceans Tales has the rest https://oceanstale.com/category/diamond-dust/

Thank you

Enjoy your reading! (≧∀≦)