 [ Symptoms ] i fell down and have a slight ache in my right side under my breast should i use a hot or cold pack [ Disease ] no a fracture ankle and influenza are not related a healthy person or one with a challenged immune system can develop influenza if they are not immunized it is not typical for anyone to get influenza in june if you are in the northern hemisphere so how sure are you that it was influenza a self diagnosis can be incorrect influenza has a 24 to 72 hour incubation period so getting any illness three weeks after your injury is not a logical association