I honestly think it has to do with the doctor. I see multiple doctors (GP, OBGYN & FS, plus the doc who did my D&C at the pregnancy loss clinic) and each one basically said something different.
My GP is very old fashioned. She told me to wait AT LEAST 6 months!!!
My FS said to wait two months, but I think that is mostly because it takes two months for the results of the tests they are doing on my embryo to get back, and it will take me about that long to get back on Metformin.
At the clinic they said you can get pg right away, but for everyone's peace of mind you should wait until after your first AF after the loss. This is because it's really hard to tell your dates if you get PG right away because your hormone levels could be elevated from the previous pregnancy, and it can just cause a lot of stress on you when you don't know the dates, are told one thing and find out it's another and worry that something is wrong.
My sister is also a nurse and told me the same thing. She said basically it's easier for doctors if you wait 1 cycle, because then they can tell the dates etc.
So, I think it really depends on the doctor. Of course, it also depends if you're personally ready to try again, but I think the consensus of most of us here is that we all want to try again ASAP!
Good luck to you!!!