No day off

My sister is going away for a couple of days.She has asked me to work in the office and answer the phone for her while she is gone. Since the 3 days I agreed to work for her are my regular days off, I will be working for 13 days straight without a day off. Luckily the pay is good and it will give us extra money to spend in Disney in November, but 13 days with no day off.....what was I thinking?