The online link is your best option to track your refund. I have attached a link with more answers from the IRS as to why your refund may be taking longer to process.
There is a delay in processing the returns as the IRS is not processing paper returns at the moment due to Covid-19 and social distancing policies in effect.
Go here for stimulus info: https://www.irs.gov/coronavirus/economic-impact-payments
This FAQ site may also answer your questions.