Because the IRS is just today, Monday, January 28, 2019, officially beginning to accept tax returns.
Many states are following the IRS and will begin to process today, but some states will not begin to process until later in the week. Your return will show as pending until then.
Please follow this link to check again later today or tomorrow:
https://turbotax.intuit.com/tax-tools/efile-status-lookup/
