Inadvertent Gauge Increase

I need to return to checking the gauge as I spin. My gauge has inadvertently increased on two recent skeins. One skein was supposed to match a previous skein (which had gauge creep already itself) but this skein doesn't match at all. It's unsuitable for the scarf project and I'll have to spin another skein to replace it. Not that I mind spinning, but I regret not hitting my target because of mistaken, careless thinking.