<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi I have been on birth control for 5 years, First i had the mirena for 5 years then i switched to the depo shot in may and i got another shot in july, im due for another at the end of this month but all of a sudden i started spotting on tuesday, now its saturday and now im its heavy bleeding... what could this be?  <response>: Depo-Provera me Chat Doctor. Common side effects include nausea, stomach crampingbloating, dizziness, headache, tiredness, breast tenderness, decrease in breast size, acne, hair loss, or irritationpain at injection site. Serious side effects: 1. Menstrual periods that are heavier or longer than normal; 2.sudden numbness or weakness, especially on one side of the body; 3.sudden severe headache, confusion, problems with vision, speech, or balance; 4.chest pain, sudden cough, wheezing, rapid breathing, coughing up blood; 5.pain, swelling, warmth, or redness in one or both legs; 6.fever; 7.nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice yellowing of the skin or eyes; 8.swelling in your hands, ankles, or feet; or 9.symptoms of depression sleep problems, weakness, mood changesSo change in menstrual bleeding and heavy bleeding are side effects of demo shots. I suggest u to consult your treating doctor if bleeding wont subside.In the meantime 