Smoke out exhaust upon start up

When I start it up it blows out smoke from the tail pipe for about a minute then stops. I was told it needs a head gasket. That when it sits a valve is open and it is leaking into the valve and burning the oil when it starts. Do you think this is the problem? It runs great. No engine light is on. No misfiring I just have to keep checking my oil and I would like to get it fixed But I want to know what it is before I take it somewhere because I am a girl and do not want to get taken advantage of.