Is this okay?

This is baby# 4 for me and my husband, but is it okay that the test line is staying the same color pink? Like its not getting darker and its not getting lighter. The bottom test is the one i had just taken right before i took the picture, so it hasnt gotten darker yet at that point. Currentlyall tests are the exact same- just wanted to make sure everything is okay. My first appointmentis the 29th.