Read the following context and choose the best option to answer the question.
Context: I had my first implant inserted in the UK in 2001 , and had it removed after 3 years . I only had one period during that time . After having a baby I had my second implant inserted , but started having periods every 1 to 2 weeks , which brought with them serious back pains . I had the stick removed but continue to have periods ( to date 11 in 21 weeks ) .
Question: What may be a reason for implanting a stick in your body ?
Options: 
- For birth control .
 - For a certain disease .
 - For pain .
 - None of the above choices .


For birth control .