You could say: However, my flight home was cancelled. So I was able to stay longer than I [had] planned because I had to stay for an additional 2 nights. It was a nice summer vacation for me!!

I came back to italki after a long time. This summer vacation has recently finished and university classes have resumed. The big story from my vacation is the fact that I went to Okinawa! It was my first time traveling there so I was really looking forward to go before my trip started. I planed to go to JUNGLIA, which is a theme park built recently, swimming at a hotel's pool and at the beach and going to Kokusai Street. I enjoyed all my activities. However, my flight was canceled when I went back home. So I was able to stay longer than I planned because I had to stay for an additional 2 nights. It was a nice summer vacation for me!!