Steroids for baby lungs?

Sabrina 👼🏻👼🏻🎀

So I have to get steroids for my baby’s lungs in case we have to take her earlier than 38 weeks. I’m nervous about because i dont know what to expect. At the hospital where they do it they also require I stay for a nst after and that makes me nervous like why? Will it harm her than do good? Just need some reassurance is all. I’m trying so hard to stay off google.