I need an explanation

Madalyn
I have been getting positive tests for days now and then when I tested today all of the sudden they are negative. I have had no cramping and have not starting any bleeding at all. Not even spotting. I was on clomid but read there was no hcg in clomid to create the false positive. Top from Saturday and bottom from today. The positive was 1 day after my missed period. 
Yes I did call the doctor and they don't understand either. Going to go in this week for a blood test.