Well, yes, but so what? Think what you've learned - you've learned how to decrease. You've unknowingly learned a technique called "short rows," where you don't crochet into every stitch, but turn before the end. It's a technique sometimes used for decoration, sometimes used for fitting, like under the armholes of a sweater. You can see what happens - you get a diagonal line.
So that's what happens when you don't stitch into every stitch - you decrease the length, and you get short rows. Now you know.
That's why I liked making granny squares when I was a teen. Also, if I messed up one square, that's all I had to re-do.
I was making the turn chain but I was probably working into it thinking that's where the next sc would be. I also was working into the next stitch from the hook not thinking it was the 2nd one from the hook. I may try a small patch of 10 or so chains and go up five or six rows and see what that looks like. If its another triangle, I've made a crochet Barbie bikini for my DD. lol.
That might be the problem, not making a chain stitch at the beginning of the new row.