I have been on the pill now for
a few years, and I just learned about ParaGard-- unlike the other IUD mentioned, this one
has no hormones, and once inserted by the doctor, it lasts for
up to 10 years, but you can take it out whenever you want. According to the website, since there are no hormones, you can start trying for pregnancy
immediately after you take it out, and on the flip side, it supposedly begins working the day you have it put in!