Thank you all for the suggestions!
Unfortunately I screwed up my stitch count somehow in the beginning and ended up with 90 inches instead of 70. Oops! ???? And silly me, i did not measure it until I had about 12 rows done. Of course each row alternates colors and I'm using a crocodile stitch which already hogs up yarn, so ripping out and starting over will waste a lot of yarn, seeing as the yarn is cut at the end of each row.
I am going to try the Bobby pin suggestion. I thought of using safety pins but I did not want to snag up and pull stitches uneven while it's pinned. I think the Bobby pins should work better because they will just slip off if it gets pulled to much.
Actually I will probably be ripping and restarting. As I laid it out to try and pin it, I noticed how terribly uneven it is so far. 99 inches on my first row and 108 on the last I did. I must have pulled my stitches too tight when I started. ????????
At least I can fix the width of it!