Teething or Sick...How do you tell?

My son is 7 months old and is teething, I can tell because he's chewing on everything and drooling like crazy! BUT about 14 days ago I got a cold virus (fever, runny nose, incredibly sore throat, body aches) which led to a stomach virus a few days later. I went to the doctor and found out it was a virus. About 10 days ago, my son got the same symptoms (runny nose, fever, fussy, not sleeping well), then it started with the diarrhea a few days later (just like mine). His fever was over 99 for about 5 days, but now it's gone. The diarrhea has almost cleared up, he just goes once or twice a day now, which isn't normal, but mine isn't normal yet either. But for the past 2 days he's been INCREDIBLY fussy! Every little thing makes him cry, you can't put him down without him crying and he's waking up 3 times a night, which he NEVER does. This kid is normally VERY happy and sleeps 12 hours a night and 4 hours during the day...and he's not even taking his daytime naps right now. Do you think he's still sick? Could it have turned into a sinus infection (even though he doesn't have a fever anymore) or do you think the virus isn't what's making him so incredibly fussy, it's the teething (even though I can't even see a white tip cutting thru yet). Any experienced parents help would be greatly appreciated :). Thank you