hopeful You are not selfish. And you are also not alone. My Papp-A is also abysmal (0.14), being the main factor (apart from my age) that has made my risk for Down's so high. And yes, I also worry about what this might mean for later in the pregnancy (if it's confirmed that baby doesn't have Down's).
Papp-A levels can be influenced by a lot of things - bleeding, weight, diabetes, smoking etc. And I'm sure that there is more! Protein regulation is a very complex process, and lots of factors can determine if levels are high or low.
They will monitor you very closely, try not to worry. Nothing much can be done anyway before the 20 week scan; I've been told that this would be the earliest next check (depending on how my Harmony results are and what I do with them). Then they will see how things are, and if anything doesn't look as it should, you will be getting regular scans etc. afterwards. It's always a waiting game, unfortunately!
For what it's worth, I have read lots of stories where women had the same, and everything was perfectly fine in their pregnancies and with their babies. All hope is NOT lost! If everything else is looking good, all the chances are that you will be fine. Try not to worry (easier said than done, I know!).