Find My Iphone

Hi, this is saidal
My IPhone 7 is recently stolen by one of my relatives but I am a little bit doubtful about it and want to ensure myself.
I tried (Find My IPhone) app and the locator showed my homes location then when I was talking with family about the Apple ID and its password then it went off and I was unable to locate it anymore.
Is there any other way to locate my iPhone like example using its serial number or any other info inserted in its box.

Help me please.......