Head gasket?

I drive a 2001 Mazda 626 and when I was driving my car to work this morning, I was stopped at a stoplight and I noticed white smoke coming from underneath my hood and it smelled like coolant burning. It also appears that there is oil in my coolant. I never heard any ticking sounds the entire way to work and my engine never got close to overheating. Does this sound like a blown head gasket? If so, does anyone know A) how much that would cost to get fixed at a regular mechanic shop and B) do products like ThermaGasket work? Thanks for the help.