i wouldnt be too quick to chop it down yet. i have grown several plants that looked like male balls but later the balls opened up and were actually female buds just tightly compacted at first growth. dont worry, if it is a male you will know in about a week and you will have plenty of time to kill him before he spooges all over your female. also, you may want to take some of his pollen and polinate your lower buds to get some seeds for next time. if you dont know how to clone just google "cloning marijuana" and you will find an encyclopedia of info on how to do it. some strains clone very easy, others wont clone no matter how hard you try. the hard ones it is necessary to pollinate and harvest the seeds.
jeff