Karma or Coincidence

I've been thinking about what happened to me last week and I have started to question if the situation was karma or coincidence.  Last week along with my regular weekly check I earned a small bonus from the company for not using all of my sick days during the year.  I had planned for the extra money to cover my girls school needs as well as some funds for me to do something nice for myself.  My surgery happened at just the right time to ruin those plans because now the extra money I would have had must be used to cover what I won't be making because I am off work for a month.  So is it just a coincidence that I got sick right when I had some extra dollars coming my way?  Or did karma see fit to prevent me from spending money on something I may regret later?  Who knows?