After you file

You would have to wait until the IRS begins taking calls again to ask them about it.  You will be able to receive any additional stimulus you were due in 2019 on your 2020 return filed next .  year.  Meanwhile, you can review the calculation of your payment to see if you understand the discrepancy here:

https://www.irs.gov/coronavirus-tax-relief-and-economic-impact-payments