lalu iqbal

Assalamu 'Alaykum wa Rahmatullahi wa Barakatuhu My quote is today mornig go for fazar namaz but went in mousq jamat stand up & started namaz . but i always pray two rakat sunnat & i join in jamat . but My friend tell me why you no join jamat ? i tell him without sunnat how to join jamat . he tell me no probleme frist you join jamat & after you pray sunnat. So please tell me this is possible Or not.