Working out seems to be working out

A month ago I joined a gym. I will be reimbursed $20 if I go at least 12 times in a month. I made it by the skin of my teeth having to go five days in a row at the end.

I've tried several of the classes and I love Yoga. I've tried a step class which I found out was advanced 3/4 of the way in. No wonder I couldn't lift my legs or arms anymore by that point! I took a Pilates class that I would like to continue taking as well.

I took my measurements at the beginning and took them again at the end. I plan on doing this every month.

So far I've lost:

Chest: 1/2"
Waist: 2"
Hips: 1/2"
Thigh: gained 1/2"
Arm: gained 1/2"

I'm assuming (hoping) the gain is muscle forming. Or inconsistancies in the measurements. At least that's what I'm telling myself.