Crap...

So assuming I'm not bypassing any min. stay rules, this kind of ticketing won't get me in trouble?

I'm flying
PDX-MSP-AMS-MAD on NW Aug 25
MAD-AMS-PDX on NW Dec 17

and while I'm studying in Madrid
MAD-AMS-SEA-PDX on NW Oct 2 (saturday night stay)
PDX-AMS-MAD on NW Oct 5

I'm studying abroad and have to come home for my sister's wedding.

I really don't want to get in trouble, nor lose the miles that will help me get Gold this year.

I would've flown DL, but the flight times didn't work for the wedding and only B fare tickets were available for the long stay round trip.