Try taking cool baths too, it can help the tylenol bring down your temp. Not cold, but just warm. I had a fever of over 104 for the first week after I found out I was pregnant and Tylenol just wasn't bringing it down. The baths helped, even though I felt like i was freezing.
The antibiotics should break your fever in about 72 hrs once u began taking it. As long as you stay totally hydrated your baby will be okay for now. If your fever keeps up you need to contact your dr.