There is a shift occurring in your relationship, maybe a subtle one, but an important one all the same. The power dynamic that you're both used to is changing. Perhaps one of you is used to being in charge, and the other is used to following; if so, those roles will start to shift now, and may flip-flop before the end of this period, or at least equalize.
The partner who is used to having the upper hand could experience this as a rough period; it's no fun to feel as if your power is being challenged, especially if it's happening at a deep level that can't even be rationally discussed or understood. But this can also be a tough transition for the other partner as well. Assuming a role of power or control when you're not used to it can be scary. As a result, you may both feel strangely tense, wound up, and you won't necessarily know what to do with these new emotions you're having. Just try to stay calm, first off; worrying about something so subtle and beyond your control won't help anything. If you come to a place of greater equality, then that's a good thing; that's the way your relationship should have been all along.