Hesitation

I always knew that God had a big and indescrible plan for me but I never really knew how it would go or when it would happen. He tends to surprise me everyday with new joys in my life. What I want to know is "How do you know if something was given to you by God."
Now don't get me wrong, I know that the blessings in life are always directly sent from above but sometimes we receive things in our life that we wish for, not what God wants. So if something is placed in front of you and everything about it seems right, do you run with it or do you hesitate in order to make sure it is what He intended. This is where confusion sets in!!
Recently something has been placed in my life that seems so perfect. It's kind of like an answered prayer but it is a selfish prayer on my part. It seems to be wrong timing for the way my life is heading. When I break down, besides the timing, everything thing about this new joy is perfect. So my question is do I run with it or do I hesitate?