If you mailed in the 2019 return then they must be processed before the stimulus check will be released. Due to the Covid shut down the IRS is 10 weeks behind in processing mailed in returns that usually take 6 weeks ...so all you can do is wait and check the IRS sites every few days for a progress update.
https://www.irs.gov/refunds
https://www.irs.gov/coronavirus/get-my-payment
