I see NC in your name. I'm not sure if that stands for North Carolina or something else. I'm in North Carolina and I know we had a cold wet spring, and our summer has been very wet. Usually by this time we've had weeks straight in the 90s, but so far we've only had a few days get that hot. My peppers are behind compared to last year also. It may not be anything you are doing wrong. It is most likely environmental. I have peppers in pots, as well as in a raised garden bed. The peppers in pots are light years ahead of the plants in the ground. The cold wet spring delayed the warming of the ground. I think this set everything back. If your plants look healthy, just small, I wouldn't worry too much. Good Luck!

Tim