My mom had to take antibiotics when she was pregnant with me (many years ago :) ). I don't know what type she took or how far she was but I do have discoloration in most of my molars as a result. Every dentist I went too asks me if my mom took antibiotics during pregnancy. But other than some funny color on my back teeth that only my dentist sees, I turned out fine. Talking to your doctor is a very good idea though, they know best.
I had to take some antibiotics for facial cystic acne....they were more concerned with infection. You need to see your Dr. for specifics....remeber, there is a chance it can harm baby and a chance all is well. Do not stress on this tol you talk to Dr
It can accumulate in the teeth and long tubular bones. There is a chance your child's teeth could be discolored a brownish color. There can also be a reduction in limb lenghth. There is no way to know for sure. You should talk to your Dr.