I find that when I'm purling on dpns, it's easy to get an extra stitch. You're not doing anything wrong that we can pinpoint, but the first few rounds on dpns can be difficult and just need added attention to each stitch.
Once you get a few rounds done, it should go a lot easier. Hang in there!
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry