Am I overreacting?

I've exercised pretty regularly for the last 20+ years. I've been using FB for almost 6 years. I'm not obsessed with the scale but I did used to use it just to gauge changes.

For the last couple of months my body began to settle into the five pound range one interval higher than it typically was. I haven't dramatically changed anything. And I haven't seen these numbers since I came back from traveling through Europe (21 years ago) where I lived on red wine and cheese. And Nutella.

Could this be my thyroid? Or maybe I'm premenopause? It's just that abnormal for me. Obviously I'll ask my doctor. But I'm wondering if there are any other women in their 40s who've experienced this..