my sis-in-law is RH- she didn't get her shots until she was about 12 weeks with either of her children! she miscarried in end of feb 09 and didn't get the shot and ended up getting pregnant on first of april 09...so far so good & it's twins! she got her shot with the twins in june!
if the miscarriage was early there probably wont be any problems from it. Do you know if your husband is also rh -. My last miscarriage was at 6 weeks and the doctor said it was early and rhogam was not needed but luckily we found out my husband is also rh - and now i don't have to worry about it.
Well the Rhogam (or lack of it) won't affect conception. But I would definitely go get a shot now.
Also know that it can take 6-12 months for a couple to conceive. Keep in mind that you ovulate about 2 weeks BEFORE your period, not after a period unless you have a typical 28-day cycle. GOOD LUCK!