What are the odds for this ?

I have a question for you mathwizards.

I played at an onlinesite and lost for 15 straight hours. EVERY single hour my bankroll was smaller than the previous one. The 16:th hour I made a profit of 1 big bet then went on a 4h losing streak again (bankroll smaller than the previous hour). I then cashed out and never went back. I continued to play at the sites I usually play though. This happened at a new site for me. I didn't play for 20h straight. It happened during 4 days and the beats were just amazing.

My winrate at all limits I have played online so far is over 1 big bet an hour (over 2000h online) and my SD is about 10 big bets/h (actually smaller the higher the limit). I log all my sessions in StatKing.

For a losing player the odds of this event would of course be smaller but for a winning (like me) I guess it's pretty high. Just to flip a coin and get it tails 15 times in a row is pretty hard. Calculating that is not very hard.

But would anyone of you care to do the math including my winrate and SD in the calculations. I would be happy enough to get the odds for the first 15h and If anyone would do the math for all 20h even happier.

Sorry if my english is bad. Im from Sweden.