If the doctor offered it without your asking for it then I would guess that is a real offer.
Any good doctor who is dedicated to his patients might be willing to do this.
This would especially be true if you had a relationship with him before your husband passed.
(I'm sorry to hear of this and hope things get better for you).
The doctor had no reason to call and offer his sympathy. That pretty much convinces me that he was being sincere
Does this help?
It sounds like a good idea.
You might want to bring along a small gift, even a plate of cookies for him (and maybe his staff) if you are going to show your appreciation.
I don't think you have to feel any pressure that you need to go
It seems to me that he left it open to your desire
Have a great day