Some medications are considered safe during pregnancy. Including actifed, benadryl, claritin, chlor- trimeton, dextromethorphan, guaifenesin, halls lozenges, nasal crom, rhinocort aqua, robitussin (plain), saline nasal spray, sinex/ neo-synephrine nasal spray, sucrets, sudafed, sudafed PE, Tylenol Plus, Vicks 44, zinc lozenges,and zyrtec.
Ask your dr if they have a list so you can keep it on hand depending on your symptoms and illnesses. :-)
With all 4 of my pregnancys my dr always said that it is much better to have a mom who feels better and handles symptoms than to have a mom who is so tired, wiped out, stressed, and sick. THAT will have more effect on the baby's well being than taking one dose of a medication. But I am not one to dope up on meds unless I really need it... If you take them just to take them and take them for a while, then that will have a negative effect on baby no matter what is in the meds...
So in other words, do what you gotta do, but do it sparingly. AND REST!!!!