I’m knitting along just fine when after about 8 inches into my scarf the pattern is now showing up on the wrong side. What did I do?
The pattern is
Row1: k4, [k2tog]3x, [yo,k1]5x, yo, [k2tog]6x, [yo,k1]5x, yo, [k2tog]3x, k4
Row 2&3: knit
Row 4; k4, purl to last 4 sts, k4
My guess would be that you might have forgotten one of the two knit rows somewhere. You can give yourself a good lesson in reading your knitting if you start several inches before the change and ‘read’ each line- point out to yourself row 1, row 2, row 3, row 4. Then by the time you get to the change, you might be able to recognize what you did. 
Yes, you either forgot one of the plain knit/purl rows or did one too many. Look at the rows as Abbily suggests and you’ll find the one that’s out of place.
When doing patterns with multi-row repeats, I always make sure I stop in the SAME place each time. It desn’t necessarily have to be at the end of the pattern, just pick a good stopping pooint for you. That way, when you pick it up again, you always know where to start again .