printf anomaly after “fork()”

Reference:

1. stackoverflow: printf anomaly after “fork()”

#include <stdio.h>
#include <unistd.h>

int main()
{
    int pid;
    printf( "Hello, my pid is %d", getpid() );

    pid = fork();
    if( pid == 0 )
        printf( "I was forked! :D %d\n", getpid() );
    else
    {
        waitpid( pid, NULL, 0 );
        printf( "%d was forked!\n", pid );
    }
    return 0;
}

/*
OUTPUT:
Hello, my pid is 60I was forked! :D 61
Hello, my pid is 60 61 was forked!   
*/