Even if you feel placid when you're on your own during this three-week period, you'll both get worked up whenever you get together. You'll circle each other like a couple of alley cats, backs up, teeth bared, ready for conflict. If you live together, this could be an especially rough period because there's no place where you can get away from each other, and territorial issues loom large now.
You might get into silly arguments about who did the dishes last or which one of you needs to make the bed in the morning. Though these little spats are over minor things that wouldn't normally bother either one of you, they speak to a deeper issue: You two are working out some inner aggressions that usually lie dormant, which have to do with independence and standing up for your own perspective. When we get into relationships, we naturally tend to suppress parts of our own personalities in the name of togetherness and true romantic unity. But that can lead to some serious feelings of rebellion from time to time, and that's what you two are experiencing now. So play nice! But do use the energy of this period to get in touch with the real, inner you.