Its quite possible to have PTS and not PTSD. That is, you can have some of the symptoms without the full disorder.

I think that since you only have symptoms when confronted with a direct trigger, it doesn't sound like full blown PTSD. PTSD is a disabling disorder with symptoms that pop up out of the blue.

Its not a good idea to self-diagnose as the diagnostic process is a lot more involved than going down a check-list of symptoms. (This is why doctors go to med school....so that they can accurately diagnose us!)