NJ tax was received by the state on feb 4th and approved for processing on feb 4th, but as of April 1, 2019 I still don’t have my refund... Do u know why?

Once your state return has been accepted by the state, all information and updates come from them. 

For more information on tracking your state tax refund, please see the TurboTax FAQ below for more information. https://ttlc.intuit.com/replies/3300211