Confused

It's pretty easy to go from a state of excitement to disappointment.  I was very giddy the past few days because I finally found someone to work my Sunday shift!  My prayer had finally been answered!

Until today when I came home and found out the girl who was going to take my hours decided against them.  Putting me back in Square One.

I'm not sure why this is happening.  I'm not sure why God wants me to work on Sunday mornings rather than go to church and worship Him?  I trust that He knows what's best for me and is leading me down the exact path I need to take.  I'm just a little confused as to why this is what He wants.