Why did my fertile window move?

I forgot to fill in my log from yesterday, so I went back and did both today's and yesterday's just now. My fertile window moved 2 days forward, so Tuesday was the highest percentage rather than Sunday. It hanged when I entered the data from yesterday. I know that Glow's algorithm changes your window based in the data you input, but what is the biggest factor? I only consistently track my CM, mood, physical symptoms and intercourse.