Should I be Worrying?

Ok last weekend me and a buddy of mine changed my damaged gasket from the trans pan.
I been noticing recently that a slight show of smoke is coming from the vents. Ill turn on the vents and cloud of smoke comes out quickly then stops. (and it does smell like trans fluid)

I know when we did the gasket it did get a bit messy and got on the exhuast and some other places.

Is the smoke through the vents because of the whatever existing oil is burning away? Cause im somewhat worried. I hope its not another issue.

Thanks in Advance

Im starting to think that its the heater core

The smoke barely shows when im driving only intill I turn the heater on and a whoosh of smoke comes through the vents very quickly and thats it really.

its weird I dunno