I am 21 years old. I have been on the Depo Provera shot for about a year now. I have not gotten my period since I took the first shot but just started spotting. I've had headaches and felt nauseous for the past couple of days. Could I be pregnant? I also just had a UTI yesterday. They are common among the women of my family and I have had UTI's before, but I'm wondering if this could have any explanation to the way I'm feeling or the spotting that is occurring.