Can my boss see what sites I visit when using a vpn from home to the office? [duplicate]
There is no absolutely sure way, to find out. Because there might be some software installed on your system, that always tracks your actions.
But you can find out, if your Traffic runs through the VPN.
Just visit whatsmyip.org with and without VPN, and compare. If it's the same IP, it looks like your traffic is not affected by the vpn.
If it's different, it's going through your vpn.