If any doctor EVER said I told you so after a miscarriage, get a new doctor.
Doctors are funny because they love to tell people easy things to do that they have no responsibility for - like "take prenatals, wait x number of cycles after a loss" etc but really these things aren't even evidence based, they're just things that are easy for people to do and the doctor can't take any blame for.
I do generally think that if you've had a D and C it's better to wait it out a cycle anyway and I have a guide in that thread I posted about how long to waitdepending on when your loss was.