Most people don't understand that you have to do some research before trying these "easy-going-don't-have-to-worry-about-a-pill-everyday" birth controls and with that there's issues.
I was told by my doctor and even the pharmacist that Depo Provera has had some issues in it's dark past and gave me a lot of info before I made the decision of going on it. I went on it because at the time the pill didn't fit in my busy schedule.
Although there's been arguements of depo causing miscarriages, other birth controls (like the pill) also cause miscarriages. Sadly it happens to any kind of medication you put into your body.
Do you know that depo causes blood calcium loss? It's stated in the information giving in the box that you shouldn't be on depo longer than 2 years unless no other birth control works for you... I was on it for 3 years and my bones aged 10 years within those 3 years.
The drug is a strong one but has it's drawbacks.