Blown Head Gasket, or something else?

[Jager]

Maybe time for a compression check. Keep an eye on coolant level. Any signs of leaks on the garage floor/driveway?

[RobbieKnobbie]

No obvious leaks, no puddles on the floor, and the reservoir doesn't appear to be leaking either

[Leeper]

Smoke at start-up is completely normal.

Look at the oil dipstick, is there any foam or abnormal look to it?

Can you drop your oil and look at it?

Looking at your levels isn't a fair measure of its conditions

Get it checked out quickly, if it is blown you don't want rust setting in.

Usual symptoms are:
white smoke while driving, not just at start-up
foaming in oil
different sound sometimes when engine is running
lower compression found by compression check.