hemming question

Hi, this is the first sewing project I've done for myself - only a few other projects for my daughters. I am very much a beginner. It turned out okay and I am pretty happy with myself, but the hem on the sleeves and teh bottom (I did view B) are puckered a little bit. What did I do wrong? It's almost like my stitch was too tight, but I'm not really sure, it was fine for the other seams. Any ideas? I also didn't do the bust alteration on this one, and I need to, so I want to make another one, but would like to figure out my mistakes on this one before I start again.