I am knitting a sweater. One sleeve was to long so I froged almost the whole thing. The yarn is curvy from being knit before. Now when I look at what I have knit the sts. look uneven when compared to the other knitted pieces of the sweater. Is this a common trait of used yarn or is it just my knitting?

the yarn is Plymouth Yarn - galway- 100% wool.
Thanks in advance for the help..........
Happy knitting....................
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