Hi.. I'm 16 And I'm On The Depo Primavera Shot.

Hi.. I'm 16 and I'm on the depo primavera shot. My boyfriend and I were having intercourse and it was unprotected.. He accidentally ejaculated inside me, now I've had the shot for 2 months and my doctor said my shot would be fully effective after seven days. I'm really confuesed because some answers online stated that it takes two shots to be fully effective.