We with my wife were reading fairytales aloud for our baby
Also my wife was listen to classical music a lot.
I was writing for https://edubirdie.com/blog/chicago-manual-of-style-quick-guide and read a lot of researches about pregnant period. Good prenatal care is essential for you and your baby. Watch what you eat, take prenatal vitamins... It's also very important to exercise regularly and have a good rest.