2007 kia sportage cooling system

I have a 116000 miles on my car which is a 2007
Kia Sportage and I've really not had any problems
with it ..we have had exceptionally cold weather
here in the Midwest.. I live in Wisconsin ..the last
couple of days it's been - 50 degrees and when I
went out to start my car yesterday just to make
sure it started it did start and I let it run for 10
minutes when I came back out  my antifreeze had
leaked onto the ground and I did notice that with
my exhaust in the back I had a small like pinhole
exhaust coming out in the front of my car which
makes me think maybe I have a leak somewhere
...I didn't know if this antifreeze came from maybe
the Overflow because it got so cold but I've never
had a problem with it before.. I did take my car for
a couple miles and the heater was working fine
and it didn't overheat so I'm not sure if I need to
worry about this antifreeze leaking or if it maybe
came out of the Overflow being the car being so
cold...