Too many frames?

I’m making a cartoon. it’s up to about 3000 frames long. I’m using 24 fps. playing it in the the editor is too slow on my computer, so I publish it to watch it. I got tired of watching the whole thing just to see the part that I just added so I put a temporary gotoAndPlay(2670); or whatever I want it to start at. but now it’s only going to about 1600 when I watch it even though I only have one action in the first frame and when it hits the end it goes back about a 40 frames and just loops that small little part. do I have too many frames or something?