@bragih great question and this is something I have thought about a lot over the years. I'm in the same boat as you on this one....
I do call each work a photo. Times are changing and as long as you mention that it is a reflection of how you saw the scene there is nothing wrong with it. The only problem arises when you enter it into competitions or galleries etc, then you must disclose what you did to it and stay within the rules. Thanks for commenting and I hope that explanation helps :)