It's probably a cold. There's no real way of knowing for sure, but even if there were moderate fever I wouldn't worry too much!
This is the best, most comprehensive discussion of colds I've ever come across, from Dr. Sears' site
If he does develop a fever, be sure to check out the information on that site about fever. It is enormously reassuring.
My 14-month-old has a cold right now with no fever but has had a streaming nose for several days. I give her homeopathic pulsatilla for congestion twice daily, put a little Herbs for Kids brand echinacea in her water cup, nurse frequently, sit in a steamy bathroom if she seems very stuffy, use a saline spray (but one at the grocery store or drugstore specifically made for noses; it's buffered) and bulb syringe to suck out the snot and take echinacea with Vitamin C for myself. I avoid over-the-counter drugs, since the side effects can be nasty.
Get well soon!