Speak to your doctor, but I have been told to wait two weeks or until after the first normal period before trying again. But I have heard and experienced that fertility is sometimes enhanced for the first few months after a miscarriage. I don't know if there is any medical evidence to this but lots of anectodal evidence.
Someone posted "Well a doctor always recommends to wait 6 months after miscarriage or abortion...." This is simply incorrect. After certain complications like a molar pregnancy you have to wait 6 or 12 months but that is due to the need to monitor for a return of the condition and not because of a risk to the next pregnancy. (I do not live in the US -- maybe there they say wait 6 months? If so I think it is a shame.)
It may be that a pregnancy after a miss will be considered "high risk"; I think this is even if it is not right away, but most of the time the next pregnancy is OK, from what I've heard and seen (just as examples after my first miss I got pregnant after one normal cycle and the pregnancy was called high risk but everything was fine except a few weeks of light bleeding. My friend got pregnant without even one period and everything was fine.)
Hatzlocha!