Why am I adding stitches?

I started to knit “Whisper Soft” from Quick Knit Baby Afghans by Evelyn Clark. I have made 3 other afghans from this book without problems. I am increasing additional stitches on rows 5&7, and cannot figure out why? I will have a triangle soon. Has anyone else had a problem with this pattern? Does anyone have any suggestions?
Thanks

A couple ideas come to mind.

Are you knitting and purling in the same row? Be sure to bring the yarn from the front to back and back to front BETWEEN the needles. In you go over the needles you’ll be adding a stitch.

Sometimes the stitch at the end gets turned so that looks like 2 stitches. make sure the yarn is coming off the needle correctly/in the right direction or you might mistakenly start the next row by adding an extra stitch.

If the pattern tells you, or you can figure out the number of stitches in a pattern repeat you could do a swatch over only a couple of repeats and see if when you work it carefully you gain any stitches. In other words maybe that will tell you if there is a mistake in the pattern or if you are goofing up somewhere.