What is this symbol on The upper left side ? The phone Symbol?

Hello momchil210,

Welcome to the Apple Support Communities. I understand there's a concern with a symbol that is appearing on your iPhone. I'll explain.

A phone icon appearing there usually means a call is in progress or call forwarding is enabled: Status icons and symbols on your iPhone

If the symbol doesn't disappear after ending a call or it is intermittent, try restarting your iPhone: Restart your iPhone

Thanks.