Molisa - great question! The answer for you and your DH depends on a lot of factors, like money for one -PGD is so expensive!! How many cycles you are able to undertake financially is a huge consideration. And how important to you and your DH is it that the child is genetically related to him? From what I've read, many men find it hard to use a donor but it sounds like your hubby has got his head around this already. How important is it to you that your child is is genetically related to your DH? If I was in a heterosexual relationship, I imagine it would be really important to me that my children were genetically related to my partner, but my DP and I were always going to have to use DS. I can only imagine that this must be a really hard decision for you also.
Then there's the emotional side... how many PGD cycles do you have in you? Your feelings about this may well change after each cycle. After our first PGD cycle yielded 0/4 normal embryos, I was completely and totally devastated - but by the start of the next month, I had decided I was going to keep doing it until it bl***y worked!!! I had had enough!!!!! I was going to show this bl***y PGD who was boss!!! I wasn't ever going to give up! Actually I probably felt realistically that I could do 4 PGD cycles in total; that was after 2 previous fresh normal IVF cycles (plus 2 devastating miscarriages and 5 FETs too). But I was aware that I might have had enough after the 2nd PGD cycle too... it was an hour by hour changing feeling/decision for me!!!
And we got 3/8 normal embryos that 2nd PGD cycle. The FS and counsellor said people often have to do 3 PGD cycles to get a normal embryo.
The final reality is, if you do keep going and going, you will most likely get there eventually - it's what you lose/miss out on along the way (money, mental health, holidays, friends...) that might stop you. So I'd strongly encourage you to keep going if that's what you and DH want. There are no guarantees with donor sperm either! I can tell you all about that!! Good luck with your decision! Can't wait to hear what you decide.
PS the fact you had 3 testable embryos is great positive predictor too like Kmn says... just a matter of time until you get a normal one!
PPS Good news that your FS wants to change protocols too! Just make sure he increases the dose of FSH!