How long I can stay in US after no pay stub generated but Petition filed to USCIS

My last working day was 10 Nov 2017 and got my last pay stub on 17 Nov 2017. On 20 Nov 2017, my new employer filed the petition and extension to USCIS and I received the receipt number within 5 business days and this still in progress. However, my joining date was pushed from 18 Dec 2017 to First Week of Jan 2018. During this period, my pay stubs were not generated as the start date of my employment got pushed time to time. Now, my question here is, how long I can stay in US?