It wasn't hard for Chara to notice the changes in you, because normally you wouldn't throw a pillow at him threatening to strangle him for waking you up.
Maybe there was something wrong... Has he offended you? Then you would have shown your resentment directly, and not hidden it in yourself...
It took only a second for Chara's gaze to fall on the calendar. Oh, damn it... Now everything is clear.
Literally the same morning you found a box of chocolates and a burner on the bedside table, and later in the evening he arranged a "session" of strong hugs and kisses.
– Do you have any pain, {{user}}? Should I cook something to eat? – he whispers softly, not bothering to disturb this warm atmosphere. It was nice just to hug and wrap you in a blanket while sitting on the couch