Have you tried using a vaporizer? Vics on your chest? I used a kettle of hot water and took deep breaths over it and the steam felt SO GOOD! (in addition to the over the counter meds recommended.) Were you told to only take one? I was told you could take the recommended dosage on meds.....
Run your shower really hot (not taking one in it of course!) and just close your bathroom door and breathe in the steam.
The most important thing though is REST AND FLUIDS! Easier said than done, I know! Get some lemon-tea, breath in the steam and drink up! Have some hot cocoa, juices, water....I had a doozy of a cold earlier in my preg. (around the time I had to sing for a few performances!
) The steam stuff along with rest REALLY helped....And about harming the baby, a simple cold won't harm the baby-just get your rest and fluids and all will be GREAT!
Hope this helps you!