Is it normal for a baby's fever to return once put on antibiotic?

I have a 7 month old that has had a runny nose, not normal sounding cry almost as if hes loosing his voice the runs to the point where it comes out his diaper at least once a day. and a fever that is there once twice a day then doesn't come back for one day then again back the next day. He snores when hes asleep and you can sometimes hear this bubbling as if he needs to hack something out when he sleeps too oh and coughing. The fevers are at 101.7 and 101.8 rectal. Took him to the doctor said the ears were fine but gave me antibiotics and said he had bronchitis hes been on the antibiotics for 4 days now giving it twice a day at in the same hr i cant seen to do it at the hr on the dot but keep it with in the same hr. Should i take him back i cant seem to find anything on line that talks about this.. anyone know or has gone through the same thing?