Did you call your primary doc or your obgyn? Obgyn knows what categories medications fall into and if they are safe. I was prescribed amoxicillin for my sinus infection and told no OTC meds except baby Tyenol and saline spray if needed. But med recs seem to vary from doc to doc. You can always look up the mess safety categories yourself.
If the dr knows you are pregnant and prescribed it, i think it is safe. I don't know that medication (i live in a different country) so can't help further. Sorry