Forest Glen is a stop on Matra's Milwaukee District/North Line so your trains will be going to Union Station.

When you get into Union Station there is access to Madison Avenue from the Milwaukee District platforms which will reduce your walking time to North Wacker Drive. This also saves about two blocks of walking outside when there is bad weather.

Also when you are heading home be mindful there is a Milwaukee District/North + West Line and North Central service all sharing the same platforms on the north side of Union Station. You should look for the signs at the entrance to the platforms to make sure you are getting on the right line and that the train stops at your station.