I was going home from class today and I went up a hill. I was going 50 as the speed limit was 45 and my car wanted to downshift from overdrive to 3rd. It shuttered and shook until I was at the top of the hill and never downshifted. I took it for a drive a few minutes ago on the highway and noticed the shutter again, only it was on level ground and I made it downshift. Ity shuttered for a second and downshifted when I pressed the gas in a little more. Any ideas what this could be?

And for the love of God, please dont say the tranny. Thats alot of money.