Don't worry--the antibiotics just irritated your intestines (sorry if tmi). It happens to me every time I take them, especially zithromax...ugh. It's not going to hurt the baby--the reason it's green is because it's moving through too fast...again, sorry if tmi! My doctor said when this happens you aren't losing any nutrients, just water--so be sure to drink water. Try eating some yogurt and if it still doesn't stop, ask your doc if you can take a probiotic suppliment (be sure to ask first cause I don't know about this during pregnancy but it's what I took a few times when I wasn't preggo).