Recover Your Deleted Messages On Whatsapp
Connect your mobile with your pc via USB cable.
Go to folder named whatsapp/Databases
Two files are there named msgstore-yyyy..dd..db.crypt and msgstore.db.crypt
msgstore-yyyy..dd..db.crypt file contains all the messages sent or recieved in last 7 days.
Open it with notepad or wordpad to view and read messages.
Use Multiple Whatsapp Account On Same Phone
It may be that you have various mobiles with you and in that case a person tends to have more than one whatsapp account. But once you lose or break the old phone, you always wish to use it in your favorite phone. But is it possible. Yes its possible with help of an app.
Download and install parellel space app from google play on your phone
Add accounts over it and run more than one Whatsapp account via it.