It is my understanding the after a D&C you can try right away as long as you feel healthy... might make a call to the doctor that preformed it to check, but that is what I heard on this site many times...
As for are you too old... I am 49 soon to be 50 and have been trying for 3 yrs.. Have had chemical pregnancies at least 3 times... I am taking a break from TTC for three months while I get into better shape... I have a posting in TTC over 40 that will tell you all I have done to assist my body in conceiving... There is also a post on the same forum by Sherri... that has great inspiration... I am also doing a 21 day fertility challenge on another website... Natural Fertility . com ... which another member here turned me on to.. it has lots of information about getting pregnant the natural way with out the drugs and cost of doctors and such... I did have some tests way prior to starting all of this here and was told that I have a progesterone issue... and if you read that post you will see I am addressing that...
Good luck!!! There are many women on this site who are over 40 and conceived... so it is up to you... There is a lady named adgal (who is taking a break from the site), but she had her first child at age 40 I believe and is now pregnant with her second... and will be 42 when she delivers.
Welcome to the site and SSBD to you (super sticky baby dust)..
I'm so glad you posted this - I'm 39 as well, and had a d&c on 11/10 (was 9 weeks pregnant but lost the baby at just over 6 weeks). The hubby and I have just started seeing a RE in the hopes of getting pregnant again as soon as possible, and for what it's worth, the RE was all for it.
But I know how you feel - it's scary because we don't have the luxury of time on our side. Guess all we can do is take care of ourselves and hope for the best.
So don't say you're too old! Because that would make me too old, and dam**t, I'm just not ready for that! :) At least we both know we can get pregnant, right? That's half the battle right there. And from what I've been reading, it seems that the whole fertility factor seems to nudge up a bit right after a d&c... I'll keep my fingers crossed for you!
As for how long to wait. I am assuming your blighted ovum was diagnosed first trimester and the D&C was without complication? If so, then typically your Dr. wants you to wait one cycle. I have had 2 D&C's and that is what was recommended to me both times.
I asked why that was. My current OB told me it was more for dating purposes then anything and with an early loss there is no real risk to not waiting. Now, I would never ever contradict medical advice, and your Dr. knows your situation better then anyone, so he or she is truly the best person to advise you. I can tell you that I conceived my now 10 month old son immediately following a natural miscarriage with no cycle in between, and he is healthy and fine.
Good luck with whatever you decide.
Oh, and as for being too old...nope, not in my opinion. As Raven mentioned, I had my son when I was 40 (one week before I turned 41 actually) and am currently 6 1/2 weeks pregnant with my second child. I will be 42 in January. The right age to have a baby is a personal decision. For me, having a baby in my 40's has been a very positive experience and I have not a single regret.