If you have a temperature it's really important that you take Tylenol to get it down for the baby's safety. But as with everything, ALWAYS consult your doc via phone (or, if your doc's office is as busy as mine, a nurse that works at his/her office will do) before taking something. I had a fever around 18 weeks and took Tylenol to reduce the fever - worked like a charm - and Sudafed because I literally could NOT breathe, I was miserable. I took the lowest dose.