I had a failed cycle with an ultra proven donor at Boston clinic which RE blamed on bad embryos. I moved on to SG. We had the option of paying for single cycle or doing the more costly guarantee program. We opted for the guarantee program and cycling was soooooo much less stressful knowing if it did not work we were not losing a ton of money, we could have another chance. As it turns out, I got a BFP on the first cycle and am now 22 1/2 weeks along. I do not regret spending the extra money...it was worth the piece of mind. GL to you.