I filed my 2019 return and when asked if I received the 2ns stimulus I said no and it was added to the return but I did get it it What to do? 1040X now or wait?

I suggest that you wait.  The IRS is very good at determining what is owed and what is not.  I expect you will get some kind of tax notice confirming the original payment. 

If you do get the additional money for the stimulus I suggest that you contact the IRS.

You can call toll-free at 1-800-829-1040 or visit a Taxpayer Assistance Center Local IRS Office .