Dead embryos? :(

On my vacation my dog recognized 7 abandoned eggs, I believe duck eggs. I didn't believe they had a chance, but 4 actually look healthy, with embryos and blood webs. One doesn't show anything yet, and those two make me worried. Are these blood rings, are they dead? When I saw they're developing earlier today I got so excited that I checked on them really often, also I don't have an incubator since I didn't expect them being alive, I just have a heat lamp and the temperatures aren't constant. I ordered one now, but it's arriving Saturday. Anyone here who can help me out, and tell me if these are beyond saving and if I did kill them?