General aviation pilot reported a near miss while landing when another aircraft entered the runway causing the landing pilot to perform a go around; while in the flare; to avoid the aircraft that entered the runway at the non-towered airport.

Narrative

On approach into HTW; frequency change from Huntington ATC was approved; I announced a 3 mile final to RWY 26 on advisory. I visually confirmed 'TX' on my radio as is my habit. There was no immediate answer on the CTAF and constant visual scanning revealed no traffic in the area. Landing and taxi lights were verified to be on as part of landing checks (verified to be operational after landing). About 0.5-1.0 miles from the runway I noticed a white and red plane entering the short taxiway between the ramp and runway. I heard on CTAF 'N(unknown) will back-taxi runway eight after airplane'. I observed the plane to be slowing down as he approached the runway intersection; apparently to allow me to land before back-taxiing. As I began my flare over the runway; the plane slowly entered the runway from my right. I immediately applied power and executed a go-around from the flare. My aircraft was loaded heavy with passengers and our energy continued to carry us to and down the runway with at least one of the mains making brief contact before we began to gain altitude. As I approached the encroaching plane I had gained 8-10 feet AGL and raised my right wing executing a 10deg left turn to increase our horizontal separation as he continued into the runway. After clearing the plane I executed a 10-15deg right turn to avoid the trees that line the south side of the airfield. After climbing enough to clear all nearby obstacles I was able to debrief on the radio with the Aircraft Y pilot. He did not hear my 3 mile final announcement and I had misunderstood his intentions. It is also my opinion that he never visually checked for traffic because at the time he entered the runway as I would have been over or on the runway with both landing and taxi lights on as well as the rotating beacon.I have identified at least two factors; and possibly a third; that contributed to this near-miss. First communication: I should have made a second announcement on CTAF when I noticed the plane entering the short taxiway; but I had become micro-focused on the task of landing and assumed he would be stopping to let me land as I observed him slowing down. It may have also been prudent for the Aircraft Y pilot to make a second announcement that he intended to enter the runway from the taxiway. Second: failure to fly a predictable pattern. I elected to fly straight into HTW; as discussed with HTS ATC; instead of flying the pattern as there was no airborne traffic in the area. Pilot fatigue: reflecting on the incident; I believe I became fatigued over the course of my flight. It was about an hour flight to Lawrence County; OH. There were many thermals over the hills in that area and providing adequate orbits was taxing. I had also flown in the consecutive days leading up to this flight. As we followed the Ohio River west to HTW; ATC advised winds 090 at 6; but my brain interpreted 190 at 6 so I selected RWY 26. This put me on an unpredictable runway since RWY 8 would have been favored. It is possible that fatigue also affected my communication as I usually make many and appropriate announcements on CTAF at any untowered airport. My approach to RWY 26 was stable and would have resulted in a safe landing despite the unfavorable wind. I used the IMSAFE checklist prior to this flight and felt that I easily satisfied each item. I felt energetic and excited when we left ZZZ.Several lessons were learned from this incident.1. Always fly the predictable and published pattern for every airport; every time.2. Make sure that I make proper announcements AND that they are received and understood.3. Ensure that airport conditions are interpreted correctly; maybe start using a visual diagram as a backup. Although this has never been an issue in the past.4. Do not assume that I know the intentions of other pilots. This has also not been an issue in the past.5. Do not assume that just because I passed all items of the IMSAFE checklist that fatigue could not set in later in the flight. Take flight duration into account; especially if the flying will be more 'active'.6. I was certain I had heard and understood the other pilot's intentions; but I had not. Simple follow-up communication would have avoided this incident.7. This incident would also have been avoided if the Aircraft Y pilot had simply visually cleared to his left before entering the runway. He most certainly would have seen my aircraft with bright LED lights and red rotating beacon just over the numbers. I was only 900 horizontal feet away; and 5-6 feet AGL when he pulled out in front of me. He did not conduct clearing turns prior to entering the runway.