Adjustment of Status - I-485

I sent all of the required documentation to my attorney 3 months ago to file my I-485 which is current right now under my employment base sponsorship. At that time the attorney told me that my I-485 case has been filed so I started waiting on receipt notice. Now, it has been more than 3 months and I still haven't got the receipt notice yet nor my check has been cashed that I sent under USCIS name for the application fee. The attorney keeps on saying he is in contact with USCIS to find out what is going on with my case and why I haven't received the receipt notice yet. But now I've to grow suspicious on my attorney whether he really filed my I-485 case or not. What steps can I take from here? Any suggestions will be appreciated. Thanks!