Almost right! You could say "Sorry. Am I in the way?" or "Sorry, am I in your way?". Note the interrogative word order. Be careful not to confuse 'in the/my/your way' (meaning causing an obstruction) to 'on the/my/your way' (meaning 'en route'). For example, when you're due to meet a friend, you might send a message saying "I'm on my way!" meaning that you've set out and you're going to arrive soon.

Just say: "Oh, sorry". Then move out of the way... (UK)