Shouldn’t line be getting much darker

I caved and did a test 3 days before period and to my surprise and joy it came back with a faint line! I’ve now done one each day, period is due tomorrow. Since I tested so early I’m not worrying like crazy that something bad might happen. Should the lines be darker by now or not since my period still isn’t due tomorrow. The one from today (bottom) is a bit darker I think Any insights or experience from you ladies is much appreciated to calm my nerves!