Mysterious extras rows while knitting in round
I've just started my first ever attempt at knitting a hat with circular needles. I cast on, made sure it wasn't twisted, and commenced with K1, P1, K1, P1 and so on to do the rib. I have a marker marking the end of the "row".
As I have finished knitting a number of rows now, I noticed that part of my knitting is looking deeper than another part of it. I thought maybe it was a freakish difference in tension, but that doesn't seem to be the problem. I counted the rows and I have 10 rows in the deep section and only 6 in the "shallow" section.
If I'm knitting around and around, in a spiral, how can I have something weird like this happen? Shouldn't there only be a 1 row difference between where I've been and where I'm going?
Does anyone have an explanation for what has happened? I'm perplexed!