How do I know if my phone has been cloned?

iPhone clones can be identified by:

checking the serial number if it is valid or not

checking if it has pentalobe screws

checking the logo

checking the welcome screen

looking for "designed by apple in California and assembled in China

and checking the built in apps ( Compact, Compass, Settings, Calculator, Music, and Photos.)

Davincci1982 wrote:

Can’t talk about it. I just want to know if their is a possibility.

No, unless you have jailbroken your device.

Because they know stuff that I wrote by text.

If by text, you mean something you wrote and sent as SMS message, then you might be a victim of what is called SIM Cloning; in such case you would need to contact your carrier asap.

If by text, you mean something you wrote and sent via the iMessage service, then your Apple ID could be compromised; you should make sure to change your password and, if not using yet, setup 2-factor authentication.

https://support.apple.com/en-us/HT201355

https://support.apple.com/en-us/HT204915

Why do you think it might be?

What do you mean it already had a number? Was it your phone number? Or just some random number? Did you purchase the phone new, or was it previously owned? Who did you buy the phone from, Apple or some other seller?

Is this your first ever cell phone? Did you not have a cell phone number previously? A cell phone company, can activate a number of a phone using the IMEI number while the phone is in the box, so if you were getting a new cell number, what you describe wouldn't be odd.

Do you have reasons to believe your phone has been cloned? If you do, describe in details what exactly is happening.

You are talking about identifying a knockoff iPhone, the OP is referring to something different.

What is that supposed to tell us?