Am I ferTiile?

Patient: I have been on the injection for 5 years and went of it because I was told if you use the injection for so long you can’t fall pregnant so I went over to the pill and since then I have been bleeding for 3 weeks in a mont and its almost for a year now could I be sterile or could I be busy becoming sterile the doctors did do a blood test on me and they told me that after my miscarraige earlier this year my chances of falling pregnant are very low now I just want to know is it possible that I am getting sterile by the moment