Answer:
What has 13 hearts but no other organs?
I contain six letters minus one and you got twelve.
I am one with eight to spare, lest I lose my one. I'm not a number. What am I?
I begin and have no end. Eventually, I will be the ending of all that has begun. What am I?
When set loose I fly away. Never so cursed as when I go astray.
No matter how little or how much you use me, you change me every month.