Yoga body improvements.

I just barely started doing yoga 3 times a week. My goal is to get my flexibility and balance back from when I used to dance full time. I also hope it helps with my abs because I also want my 2 pack back. I also do Zumba 5 times a week so I'm hoping yoga is a good balance for me in between Zumba. It will give me a day to stretch and relax.

When should I start seeing improvements in my body changing? I know its different for everyone because of diet and fitness abilities but just in general I would like to know.