Still no period but no more positive test

So I took a test last Friday around 6pm and got a pretty dark line. So I took another one Saturday morning to see if it would be just as dark or darker and it seems like it got a lot more lighter then Friday’s. I have then taken a couple more and now I am getting no lines and no period or bleeding. Any ideas on what the heck it could be!?

Top is from this morning and bottom is from last night.