What's your calories at currently and how much are you exercising. The thing goals is most people have them set up where they're competing with one another.
If you're eating strictly plus marathon training plus weight training plus whatever stress you have going on, things tend to go a little haywire. Metabolic rate can certainly drop to a degree where scale movements are hard to see, either b/c they're masked by fluid retention or your metabolism has slowed to a crawl making what should be a deficit, maintenance.
That's why I rarely have women who are relatively small already looking to get leaner do a lot of cardio. It just doesn't work for fat loss well. The body tends to resist it.
I also don't diet linearly. I institute refeeds quite often.