sorry, this isn't the answer you're looking for - I had a bad cough in my first trimester and my KKH gynae prescribed me with a cough syrup. when I went home to read the instructions and information of the cough syrup, it said that it hasn't been proven to be safe for pregnancy. thus, I didn't take it. I spammed honey instead and took a while to recover.
If your gynae said it’s okay to take, then it would be okay. Just follow what your gynae has advised you. They are medical professionals. It would be better to follow medical professionals than this platform. Your gynae knows your condition better than us do.