Fever or teething?

So my son is just about 13mo old and still doesn’t have teeth and yesterday when I got home from work I noticed his head was pretty warm. I took an armpit temp (100.3°) and a rectal (102.0°)... he’s still playing and laughing and eating though. I haven’t noticed any extra drooling or runny diapers, one of my friends says this is common with teething.. but I’d like other mamas input on this, could this be teething or should I just take him to see his pediatrician tomorrow morning?