If you mailed in your return then it will take a long time to process as the IRS is not processing any paper returns at this time due to the partial shutdown. And if you did not mail it with some sort of tracking then you will not know if it got there ... normally I would not recommend it but you could switch to efile and see if the return is accepted or rejected .... if rejected you will know if the return is already in the system and then all you can do is wait patiently.
