The recommended schedule for the hepatitis B vaccine:

 is to receive the first shot, followed in one month by the second shot.  Six months following the first shot, you should receive your third and final shot of the series. If you are committed to ensuring that you have built up adequate immunity, you can have your anti-HBs (HBsAb) titres checked 4-6 weeks following the last shot of the HBV vaccine series.  If your immunity is greater than 10 IU/l, then you have adequate immunity which is thought to confer lifetime immunity, but studies so far show 20 years.  This is because these studies are on-going!