Norska, my Fila Brasileiros tend to have their first heats at around 6 or 7 months, and they do have PMS, lol! Not only do they whine and fidget and act cranky or mopey, they try to steal chocolate
It really doesn't seem to be that they are unhappy or uncomfortable, they are just incredibly needy and crave attention - just like us human females.
It's wonderful that you're so tuned in to your dogs' emotional well-being, just bear in mind that they will use that to their advantage sometimes - and these working/guardian breeds seem to be particularly adept at it