Please turn off your caps lock, it is interpreted as yelling.

Yes, it could be from the oil change (either leaked oil, or the cap left off). Why not take it back to the place that did the oil change?

If it is cold in Chicago, then you could have a frozen oil separator, a known problem. That is what the posters above are referring to. You don't necessarily have this problem, but a mechanic could determine if it is in fact that. If so, the valve cover gaskets are likely leaking onto the exhaust manifold because of a pressurized crankcase.

You don't say what year your vehicle is, or what engine you have. How cold is it outside? All those details would help members here give you some more precise recommendations.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue