You have the highest concentration of hormones in your fmu (first mornings urine) which could explain the negatives later in the day. But not the following morning. Usually a line is a line, but followed by so many negatives I can see why you are concerned. I think that you should wait a week and test. If you still have not gotten your period by then and the test is negative, then it is time to schedule a doctors appt.
Are you wanting to be pregnant or not?