Dear Jodi16,

The shot is up to 99.7 percent effective against pregnancy. It is one of the most effective reversible methods of birth control. Of every 1,000 women who use it correctly, only three will become pregnant during the first year. A shot can prevent pregnancy for 12 weeks.

The shot does not protect against sexually transmitted infections. Always use a latex or female condom to help prevent sexually transmitted infections.

Click here for an important update about the shot.

To answer your second question, some typical symptoms of miscarriages include:

• Slight vaginal bleeding or spotting
• Severe abdominal pain
• Severe cramps

However, not all miscarriages are painful and some women miscarry and mistake the miscarriage for a heavy period or are not aware of the miscarriage at all.

Hope this information helps!

Take care,

teenwire.com^® Editors

This column is for informational purposes only and is not intended to constitute medical advice, diagnosis, or treatment. If you have a medical problem, please call toll-free 1-800-230-PLAN for an appointment with the Planned Parenthood health center nearest you.