Can Tiredness And Aches Be Symptoms Of Mono?

Hello- I am wondering if it s possible to have mono twice. I ve had it last summer for the second time and I hear different answers. I hear it can be caused from other illnesses. I was tested for everything under the sun and I m not aware of any illnesses. Everything came back fine. Yet I still have these episodes where I feel exhausted and achey and I have a flashback to mono. What could possibly be wrong?! Is my body just tired or is there something else wrong that s waiting to be diagnosed? I am sick of feeling this way. I eat healthy and workout 4-5 times a week. I should be feeling great.