Strange light

On the 25th of may at like 3am i woke up and looked out my window and saw this weird star/light in the sky so i grabbed my camera and filmed it. The video is pretty dodgy and it's really blurry and you cant really see anything but it's still kinda cool. The light was about the size of a normal star then it got bigger and bigger until it was almost the size of the full moon and then it went smaller again. It kept on getting brighter and then dimmer again for ages until eventually i fell asleep again. I haven't seen it at since and i still don't know what it was. Maybe a UFO! haha

p.s- you cant see anything until about 40 seconds into the video