I started a scarf, using garter stitch, and put it down towards the beginning of summer due to the heat and its effects on my hands and the yarn. When I picked it up again just a few days ago, I noticed that, as I was knitting, that the scarf had gotten wider. I kept counting the stitches and I still have the same number I started out with, 20, so I know I am not picking any extra stitches up. I think the problem is the tension of the yarn. I am probably knitting with a looser tension than I did before the summer.
I have needles in a smaller gauge, but I have already knitted several inches of the scarf (at least 6-7 inches worth) and don't want to tear it out to the point where it starts to get wider.
Is there a trick or something that I can use once I am done with scarf to get it looking the same width all throughout?