单身老猫，各位朋友，Please help!!

I made a mistake unintentionally by using a wrong check book to have written several ((6-7)checks. The check book I used is from a bank where my checking account has been closed but I forgot to destroy one of the left old check book. It was very similar to my current check book from another bank.

My questions are:

1) Are there any serious consequence of this mistake legally?
2) Will the bank report it as a fraudulent action to police or FBI?

Any suggestions are welcom. Thanks.