how can I tell my iphone is actually backing itself up?

I have installed the IOS 8.3 on my iPhone and re-installed iTunes on my PC. I am using an iPhone 5S and I have not had much luck with my phone backing itself up. I have a little down time and would like to know how can I verify if my phone is actually backing itself up? The backup as been stuck on step 2 of 4 for half an hour. How long should a complete backup take?

My phone has the following specs:

IOS 8.3

12.02 GB available

Phil