Hello Wobbles,
i am not a mom yet may be this month

but i have work with a lot new born babies and older ones also ...
We always say in my family a newborn never cries for no reason really (it may be discomfort by some thing that we can not see really) and it is there only way to signal it to us.
i think if you can't tell why she is crying she can not tell you why either ...
but you are her mom you will have the best instinct to tell and learn her different cries even the ones when she just want to be pick up...it doesn't have to be because sheis in a physical discomfort either they are so tiny and everything is scary for them a noise ,a smell they don't know this new world ...who knows?
i wish you the best and good luck !
hope i made sens

i think when they older they can trick you better with the pick me up think ...