Light aircraft pilot reported an NMAC with another light aircraft in the pattern at EDU airport.

Narrative

I was flying practice RNAV RWY 17 in visual conditions at EDU with no vision limiting devices. In the past; I have flown this same practice approach many times With a safety pilot and also with an instructor. Travis approach was handling me with flight following and would release me at Hapax to contact CTAF. I had just completed two approaches with no other aircraft in the pattern or taking off. On this; my third approach; I was at Hapax and Travis had just released me to CTAF. On CTAF; with no other aircraft broadcasting in the pattern; I reported 'straight in rwy 17 approach; 4 miles north at 1400 feet for a low approach.' Still no other traffic. I reported again at roughly 1100 ft straight in; rwy 17 two miles north. Shortly after I heard another aircraft report entering left down wind rwy 17. I replied to his call and asked if he had me in sight...I got no response. I called again broadcasting straight in; 1 mile north and now roughly 800 ft and asked if the other aircraft in the pattern had me in sight...I got no response. The other pilots next call was turning base. Needless to say; I freaked; frantically scanning for a visual as I see the other aircraft pass over me.In retrospect; I have learned to never expect courteous; safe; recommended radio transmissions from other pilots (even if they are an instructor) and for my part in the situation; I should have broken off the approach when I first heard the 'downwind' call. I learned a lesson here and will keep it in my flight bag.