Looks like a burundi as for the sex I am not sure how big is it. How long have you had this fish as it could also be a 5 bar cichlid would like a little more info.
Thats a Burundi 100% as for the sex wait until your fish is about 5" then do a Venting or tubing "Venting" or Tubing" actually involves viewing the sex organs of a fish in order to determine sex. Check this out: http://www.frontosa.eu/sexing.html