Need help with pattern edges

I am doing a scarf with an elongated stitch. K 3 rows then use an elongated stitch (wrap needle 3 or 4 times) then K again. My problem is the edges. One side of the scarf has a straight long edge, but the opposite side has a chain appearance. Does anyone have any suggestions for getting the straight edge on both sides? I am a new knitter and this has me stumped.

We just had a thread about that a couple days back and there’s some older ones