Couple of questions

Vicki
Sorry for the multiple questions, just looking for some advice. I had d&c a week ago at just over 9 weeks after our little one had no heartbeat.
We are desperate to try again as soon as possible, I'm still bleeding but wanted to get my head around a few things:
- if we are going to start trying again before my next period, does this pose any problems for potential baby other than dating difficulties?
- when should I get a negative pregnancy test from this miscarriage? Should I wait for a negative before trying again? 
- are you more fertile after a miscarriage? Or is this an old wives tale? 
Thanks all x