That's a silly question; you obviously don't know the scripture? Jesus told him he would deny Him before the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] crowed, he denied Jesus, the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] crowed, he remembered what Jesus said, and cried. Look at the verse numbers and their order. You will see he repented AFTER he sinned.
34 Jesus said unto him, Verily I say unto thee, That this night, before the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] crow, thou shalt deny me thrice.
70 But he denied before them all, saying, I know not what thou sayest.
74 Then began he to curse and to swear, saying, I know not the man. And immediately the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] crew.
75 And Peter remembered the word of Jesus, which said unto him, Before the [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] crow, thou shalt deny me thrice. And he went out, and wept bitterly.