I wish it didn't take so long to hear back from the places I've submitted my work too! I just sent out submissions for the first time in Jan/Feb and haven't heard back from most of the places. I have received two rejections, both of the same story-- those were the only quick responses! And I don't even like that story, I just decided to send out every short I had written recently so I learned my lesson on that. I just did some edits of what I consider the best short story I've written so far "2014" and resubmitted. It's my first experiment with futuristic writing, even though it's only a few years in the future, and it was really fun to write.
I wish that even my rejections would come faster, but I guess this is all part of the process! I have made attempts to contact one or two places, to see if they had even received my queries, and if I hear nothing soon it will be time to resubmit those as well.