This is dr. Papaqako answering your question.
The most common symptoms of mononucleosis
Fever, which may range from 101 °F (38.3 °C) to 104 °F (40 °C), and chills; Sore throat
, often with white patches on the tonsils (which may look like strep throat
); Swollen lymph nodes
all over the body, especially the lymph nodes in the neck; Swollen tonsils; Headache or body aches; Fatigue and a lack of energy; Loss of appetite; Pain in the upper left part of the abdomen, which may mean that the spleen has become enlarged.
If I was your caring doctor, I would recommend to take some Paracetamol/Ibuprofen
or Buscopan 10 mg. If the pain does not get better, or gets worse (like spreading in all the abdomen, or getting higher in intensity, or stopping your bowel movement and gases) I would advise to go to the ER and investigate the cause of the pain.
Hope this helps,