Hi Syl-
Always keep in the back of your mind that you have had one of the most profound surgeries that you can have. It's unlike any other surgery out there. It involves bionics, physics, chemistry, electrophysiology and medicine, plus superb surgical skills and anesthesiology skills. All kinds of hi-tech tests are done, all for the goal of restoring your heart back to proper functioning. Really very, very amazing.
It is the marrying of a foreign object with your own physiology. And the great news is that it's a highly successful surgery.
Because it is so technically difficult, your body needs lots of time to readjust, rest and heal. You have to rebuild the parts of your body which have deteriorated during the time you were ill. Rehab takes a lot of effort and it's tiring. while you're trying to rehab, your body is silently doing all of its own readjusting. It's learning how to go back to work again in a more normal fashion.
It's good that you are having an echo, bloodwork and a chest xray. You will know soon afterward if there are any problems. Maybe your sternum is taking longer to knit together. But there are no set timetables, everyone heals at a different rate. I think you can see it from all the posts here. Some zip through it and are back to work in 4 weeks (lucky devils), most take much longer to gather strength and to heal. Don't measure yourself by others, you are unique. It sounds as if you have good, caring doctors who will stay on top of everything for you. That's great.
As far as work is concerned, I'm sure that most of them don't know of too many others who've had such surgery, so they have no way of knowing what is involved with the healing process. I would just tell them that the surgery is not like any other, and the recovery takes a while and that you want to come back to work when you are able to do your very best, just like you did before and tell them you're so glad they miss you, LOL.
Nine weeks after heart valve surgery isn't all that long. You are on the road to recovery and you'll get there. There are always little glitches here and there. A year from now, you won't even remember them.
Good luck with your appointments and please let us know what they say.
Take care,