Medicine while pregnant

So I’m 27 weeks pregnant & I’ve been sick the whole time. Not like morning sickness (that too) but like colds, cough, congestion, sinuses, etc. and I’ve been taking medicine for it this entire time (robitussin). I mean literally every day just once daily -mostly at night time so I can stop coughing & get some sleep. I’m at the point where I’m tired of taking medicine & scared it may cause some harm to my baby from taking it so much. Am I causing more harm than good?? Any similar experiences??