I finished shark week the same day as my first injection, which was a smaller dose than what I'm on now. I expected it to take anywhere from 3-6 months from the information I had read throughout this forum and other resources. In my instance I was relatively lucky to not see a single one past my first injection. I'm glad it's gone, having a tingly sensation for days and the odd cramping session wasn't pleasant!
All the best for you! If it continues past the expected time frame, there are options such as a depo provera shot. Those might not work either depending on your body.