Lost contacts after battery ran out - any help greatly appreciated!

[jclare]

I lost all my contacts - any help restoring them will be greatly appreciated!   I accidently let the battery run out on my IPhone 4 and after I plugged it back in and it came back on all of my contacts were gone.  Everything else is still on the phone but the contacts are gone.  I am technologically challenged and did not realize that I haven't backed up the phone since September of 2011.  I thought that when I synced the phone that WAS backing it up.  Evidently not.      So I am begging for some help.  I have looked at some other posts but they all are about losing contacts after doing an update.  Please help if you can.  Thank you!