There is no way for us to tell you if something is wrong or not.
You should check the processing times at the USCIS website (www.uscis.gov) and if it is past the date you filed, then you can call USCIS and file a status inquiry (due to the fact that your case is outside the processing times).
For an answer to this question, you must go to the CIS website at www.uscis.gov, and in the left-hand column click on processing times, then at the bottom of the page, click on the Service Center that is processing your application (I-90) (check the bottom of your receipt to know whis is your service center). Then look for processing times of I-90s, and you will know if something is wrong. If your application is outside "normal processing times" call the 1-800 number on your receipt. They will probably not answer your question during the phone call, but they will lodge an inquiry, and you will usually get a response within 45 days.
It is impossible for us to give you an answer. Do you have any issues? Have you gotten in trouble with the law? Check the CIS website for case status.
Law Office of Luis A. Guerra (954) 434-5800. This answer is of a general nature and should not be relied upon as final, nor is it intended as legal advice.