Birth Control

I have been taking the depo prevera shot for about the past year. A month ago I decided to quit taking the shot because I was having problems with becoming severly depressed all the time. Also, I was getting rashes all over my body. I'm not sure what form of birth control I will end up taking but I have decided to allow this shot to get out of my system first. How long do you think it will be safe for me to be off of birth control? And how can I know when I start to ovulate again so that i can start to get back on birth control? I do not have a cycle as of now, does that mean that I am safe as long as I do not have a cycle?

Thank you for you time.