sick. med question

[themaybaby]

I've cought my son's sinus infection. I was at my OB appointment and she called in a z-pack for me. She said if the coughing was bothering me I could take Robotussin. Ill be honest the coughing is painful and driving me crazy. I bought some but checked safefetus and they gave it a C. Only human complications listed occured in 1st trimester. I'm in the 3rd.

What say you wise internets? Is it safe? Have you used it? Will it even help w/the cough?

Thanks!