Yeah, i agree, I wouldn't worry too much about it. The company probably packages nuts by weight, not count, and they are allowed to vary the weight within a certain percentage, so the calories of the nuts inside aren't going to be exactly the same in each serving. Plus, some nuts are bigger than others, lol.
Also, the calorie count of any food is really more of an average range. Calories in produce can vary depending on the soil they were grown in, how they were prepared, variations in water content, the age of the food at harvest time, etc.
Congrats on starting a new lifestlye and experimenting with new foods
This is one of the things I've enjoyed the most about changing my eating habits - trying new things.