Another simple photon experiment

G'day So here's another experiment in my mind. I take a monochromatic light source then put it through a 50/50 beam splitter instead of a double slit. On each exit of the beam splitter I put in a photon detector. I then turn my brightness down so that I can get one photon at a time. If I then look a the coincidence of the two photodetectors I should never see any signal at zero ie both detectors picked up a photon at the same time. I will get a blip at one OR the other photodector, correct? I assume this has been done very accurately