H1-B for non profit organization

I work for a non profit organization and currently on Stem OPT. My EAD expires Feb 20 2021. My organization has filed H1 petition in December 2020 with the start date as Feb 21 2021. I have received the receipt number from USCIS and they are filing for premium processing tomorrow. Will I be able to work after Feb 20th with the receipt number or an approval for the petition is required? If I don’t receive an approval or my petition gets denied how do I maintain my status?