Megmal, I can only tell you about what happened to me. For me 5 probes day 3 it was the best choice. As I am a high reponder to stimulating drugs, I had all the embryos frozen before testing and transfering them. We decided to transfer 2 hatching blasts and frozen again the remaining ones (after testing them). My doctor said that we are going to be able to use them in the future if we want, even if they have been tested and "refrozen". So I think that the "frozen issue" of day 5 CGH is no longer a big deal. My doctor is doing a lot of day 5 CGH. What I would not recommend is day 3 CGH. I have done it, and only had results of "crazy" embryos. My second doctor was very clear stating that day 3 CGH is the worse choice. If I have already done a 5 probes FISH, I would maybe go for sure for a day 5 CGH. It depends on your history, on results with FISH and on you doctor. For me the doctor makes THE huge difference, since every patient is unique. I tried 3 doctors with many faillures (no problems at all to get pregnant), and "found my hapiness" only with the third one. If you need more help or information, I am here!