I just had my baby at 44.5. I know they consider it riskier to have a baby when you are older but that is probably because the average woman may be less healthy than a younger woman. Like you, I was already healthy when I started the process, low blood pressure, healthy weight, no medications, etc. I did not have any complications with my pregnancy other than the normal annoying symptoms of heartburn and slower digestion. I had an easy delivery as well, as far as childbirth goes. I think your doctor is correct. You will be much more closely monitored during your pregnany because of your age. The doctors will check your blood pressure more frequently.
I also don't think the estrogen and progesterone support during the DE cycle is very significant. It is not the same as if you were doing an IVF cycle with your OE. So I don't think it will be a problem either.
My recovery from childbirth took longer than when I had a baby at thirty. I believe this was mostly due to my hormones related to my age. It took me 2.5 months to feel ok in my girly parts which was very frustrating.
My friend also just had a baby naturally conceived on accident and gave birth at 44. She also did not have any complications.
I hope this helps a little. As long as you have good medical care I think you will be just fine.
. Oh, and only transfer one embryo. Twins would be riskier.