Christie, I plan to do more containers over the next few days myself. Here in Zone 5, in Southern Maine things are just starting to sprout in their containers. I say go for it! Read the list of winter sowable plants, but be careful of tenders like tomatoes and peppers and a few of the tender annual flowers that once you see sprouts of them you make sure they don't get frost bitten.

Christie! I am a Pittsburgh girl too! A Southside native,but now I am near Kennywood! Glad to see you here! :) I am holding off on my Zinnia and a few other annuals because too many of my tenders have sprouted so quickly,I am hoping they will make it through these 30 degree nights we are in for. I am sure you have plenty of time,you figure we have a whole month before we can plant out. So I say go for it! Have fun! :)
~Angie