Why should someone wait after a miscarriage to try again? What are the medical reasons for waiting? Is it dangerous not to wait?

After two and half years of TTC and a grand total of six IUIs, I finally got pregnant when my new fertility doctor changed my drug protocol radically. I miscarried during the 8th week, however, which I am trying to see as just part of the cycle of life. Before going back to the fertility clinic in January, I would like to TTC on our own for a bit to see if the pregnancy, however short lived, has changed my body chemistry. Is there any harm in doing this during the month after the miscarriage. Am I risking my health or the viability of a second pregnancy if we succeed? (I am age 38 in case this matters.) Thank you!