Stuck in a method

Hallo again friends,

I am almost done with the basics of a new board game,written for my little daughter.
Where I am stuck:
The scenario is that every player has three Cards from the beginning.
Every round,if he still has his 3 cards,he gets no more.
If he has less than three,then he gets the number he needs to have 3.

So I have class Player,who has an array of 3 Cards.
I also use a class Deck,with an array of 20 Cards.
At the beginning the player gets 3 Cards from the Deck and these array places are set to null.
So I am writing a method that when a round ends,give the Player the Cards he needs:

 for(int i=0;i<3;i++){
           if (p1.getCard(i)==null){   //p1 Player
               for(int j=0;j<20;j++){
            if(deck1.getCard(j)==null) {j++;}  //deck1 Deck
                    else
            {
            System.out.println("I returned from deck card "+ j);  //Trying to trap the error
            p1.setCard(deck1.getCard(j), i);  //method to set the Card drawn to the specific place
            deck1.set_A_Card_null(j);        //method to set the drawn Deck Card to null 
               break;}
               }
           }      
       }

Instead of returning the next Card,it returns the next to the one it should, 4 instead of 3,6 instead of 5 etc.
Is there something wrong with my code?

Thanks.