Restoring WhatsApp from old iPhone to new

I have a new iPhone, restored all apps and data in no time, 

-why what’s app is taking 3 days and yet not finished restoring? 

-I’m still using the app on my old phone till it finish restoring on my new phone, when would I be able to transfer the SIM card to the new phone? I don’t want to lose any data at all! 

Awaiting support answer

Regards