[suzeeq]

Are you adding only 8 sts per increase row? And did you start with the right number of stitches in the first place?

Don't forget that you do yo and k2tog on parts of that row, not just yo k2 all across it. You should have 4 markers on the needles which are between the k2 sts. You just do a yo before and after the k2s at the markers, not all the way across the row.