Plan B One Step and Robitussin

Patient: Hi I’m 15 and took a plan b one step pill last night 26 hours a condom break, would it be safe to take 20 robitussin cough+chest congestion dm (in each liquid capsule= dextromethorphan:10 mg, guaifenesin 200mg) 12 hours after taking the plan b one step?

Doctor: