Can mono test be negative and then positive

[rosah27]

Hi guys for the past 4 months I've been feeling sick, so I went to the doctor which he diagnosed me with anemia gave me iron and pills for the nausea. Well I finished all the medicine and the nausea continued but I felt better than before. I would have rash and red patches on my knees and sometimes bruises would appear. I felt tired, sleepy all the time. Sometimes I have joint pain. It's been 4 months and I'm still feeling tired and nauseous, ooohh and by the way I've lost muscle and weight. I feel like a different person. Last week I had a blood work and everything came out "normal"..except for RDW they are high 16.4
I also tested for Mono and came back negative.
This is driving me crazy. Mom is having the same symptoms and I'm too scared that she is infected now..
Can it be EBV insted..I'm scared...need to talk to someone that has experienced this
Thank you