My line is getting lighter..

Here’s the scoop- tested this weekend and got these: first picture.

Then I tested Tuesday with pregmate strips and line was so faint I could barley see it. I know these tend to be unreliable so i ran to the store and grabbed a new test. I also know blue tests aren’t the best but that’s what I grabbed.

Today i got this: second pic—-

Shouldn’t my lines be getting darker? I called the OB and waiting for a call back- hoping for a blood test to confirm, but anyone have this happen and have a healthy pregnancy?

Any insight is greatly appreciated!