Getting married and getting married legally may be two different things - it all depends on if you have Indian government issued marriage certificate or not. If we go by that - my parents are not legally married yet ;-p.
It might seem obvious to get your marriage registered with government and getting a marriage certificate; but believe me it is not so here in India. People here generally take that step only when it is 'required' for some or the other reason; and many do not face any such reason for all their life - like my parents. This is 'the' typical thinking here, that we generally avoid the effort till the time its unavoidable. More often than not, when that time comes we do not have either time or resources to get it done and we resort to unethical ways of accomplishing that task.
I would suggest to get yours registered asap, because you never know when you might need it. With the same thought, I recently tried to get this done. As with all the sarkaari (Indian government) processes - this one is also a tedious-and-multiple-visit-requiring process. It has taken my two visits already, with nothing accomplished; coming Monday - it will be my third. I would try to explain what all you should do to get this done with least amount of pain in the next post - Getting Marriage certificate under Hindu Marriage Act 1955.
In another post - Marriage Registration, another Love affair! - I will talk about what happened in my visits for this purpose.