Confusion related to service tax of partnership firm

Dear All,

I m very confused...we have a partnership firm busniss...our turnover is 40 lacs (F. Y. 2011-12) and profit is 2 lac. and one more thing we are service provider and did not get service tax registration by last year now we have registred since 1 april 2012..

My query is -

1 . is we required to tax audit under section 44ad

2.  if we are going for audit than any problem arise coz of  we didn get service tax registration last year and our turnover is exceed  to 10 lacs

Please help me 

Thanks to all