Steroids & Breastfeeding

Kristen • Hubby & I have been together 10 years, married 11/8/14. Angel Baby - 10/22/15. Rainbow Baby Girl, Maggie, born 10-18-16!
I had to be put on a steroid pack for a neck injury. I carried my little girl in her car seat for an extremely long distance (more than I'm used to), and pulled muscle in my neck really bad. The pain from this was worse than my csection. Anyways, they gave me a steroid (L2) and a muscle relaxer (L3). My pediatrician told me to take the steroid even when breastfeeding because it was safe, I mean we give steroids during pregnancy and even to babies in the NICU. So I've been taking that, but haven't taken the muscle relaxer (if I take it, I'll pump & dump). Anyways, my question is, has anyone else take a steroid during breast feeding? What were the side effects to baby? My little girl has been crabby....I know steroids can do this to the person taking it, and I know babies who get the steroids directly can be crabby (I'm a NICU nurse)....But I just don't know if it's the diluted steroids through the milk making her crabby, or a growth spurt. Thanks for the input!