Hi there Deb
Firstly, I am so sorry for your loss, it's an awful thing to have to go through.
What you are feeling is completely normal, I was exactly the same. A few years ago I miscarried around a week after I found out I was pregnant and although it was an early loss it was heartbreaking and all I wanted was to be pregnant again. I also became very jelous of other pregnant women and became obsessed with getting pregnant again.
I don't think there's any reason for you not to start trying straight away unless your doctor has told you differently.
I personally didn't start trying again for quite a while as I didn't feel emotionally ready and was scared.
Make sure you feel ready yourself before ttc again and don't be scared, I'm sure you'll have that lovely pregnant feeling again soon.
Take care and be kind to yourself.
Janine