When can I go back on birth control? Is there a risk of going on and off again so soon?

Patient: Hello,I have been on birth control for 6 years. About two months ago I went off of it. I despiratly want to go back on birth control. My natural periods are unbearable. I now remember why I went on birth control years ago. I only went off birth control because I know I am not suppose to be on it for long periods of time. A friend told me to wait at least 6 months or I may become infertile. Is this true?? Can I go back on the pill right now? I do not want to become infertile. I need to have children later on.