Retest for Mono ?

My friend suffered through August with a case of mono that was complicated with strep throat. Against my better judgment I spent time with him towards the end of August when he said he was feeling fine.

On August 30th I started running a high fever and developed muscle aches, this quickly led to swollen tonsils covered with white spots and I developed some sinus problems.

I saw my doctor on the 31st and was checked for strep in her office (negative) and had blood work done for mono (came back negative a week later). The doctor prescribed me antibiotics, just to be cautious, which I finished and by the time the 5 day course was done I was feeling better.

My tonsils aren't a normal size yet, but I can swallow fine. And my sinuses are still messed up, but nothing terrible. But for the past four days I have been experiencing muscle aches again and feeling feverish. After finally checking my temperature, I do have a low grade fever.

Is it possible that I have mono? Do mono symptoms wane and come back? Is it possible it was too early to tell by blood work in August if I had mono? If I do go back to the doctor, what type of blood work should I ask for?

Thanks for any help you can give me.