Not to worry yet!...
No, it's nothing to worry about yet. When it smokes and doesn't clear up, then you got a problem.
The rotary seals, which are holding back the oil in your rotary chamber, around the crankshaft, will seep a bit of oil into the combustion side of the crankshaft area. When you start your engine, your burning that oil off.
It is a sign that your engine is showing it's age and will only get worse as the seasons go by. For now, I wouldn't worry about it.:cheers: