My mobile phone number is mine, but I didn't send the message.

It is possible that there is something wrong with the customer service end of your mobile phone number, such as the problem of China Unicom, but this possibility is very small.

Another thing is that there is a technology of copying mobile phone cards in the market, which is very advanced, that is, using other people's mobile phone numbers to spend other people's money to call and send text messages to their friends.

This is illegal. I think someone may have copied your mobile phone card. You can see if you have any money or go to the local business hall to pull up all the recent call records and text messages of your mobile phone.