Had anyone had any experience with their child having really bright red cheeks, which were caused by anything besides Fifths disease (slapped cheek)?

Today Aidyn has developed very very red cheeks... no other symptoms. We gave him a haircut earlier in the day, and he screamed his head off the entire time... since this his cheeks have been bright red all day/night... and I am really hoping it is related!
I have noticed it before in him... the time he went for a renal ultrasound, he went absolutely rank, and has never struggled or screamed so much in his life, and his cheeks were bright red for a couple of days after, with lots of tiny pin-pr!ck spots of dark red - like burst capillaries.

I am just praying that he, and I, have not been exposed to fifths disease, due to the complications it can cause during pg....

They say the infectious period is pretty much over by the time the rash appears, so then it is too late to do anything.
The reason I am also worried is because on Wed I developed a sore throat, headache, and general unwellness, which lasted a few days - but then didn't develop into anything further (when usually I would expect it to turn into tonsillitis or the flu)... and apparently those symptoms are similar to the symptoms adults experience with fifths disease. I will be making a Dr's appt on Monday, so I can get a blood test done... but until then, am just wondering if anyone has any other experience with cheek rashes in toddlers?