Positive followed by negative tests

[journolady]

We are trying to conceive baby no 2. My cycles are 35 days and I'm only 2 days late.
I took a clear blue digital yesterday lunchtime after feeling incredibly faint in a shopping centre, it was negative.
I then took a cheapy Amazon test with my first morning pee today and it seemed to turn positive within the time frame. I was overjoyed and took another test within the hour just to make sure. Big fat negative. Having read numerous threads on here, I'm confused as to whether it was a dud test or possible signs of a chemical pregnancy. Has anyone been in a similar situation?

Your first wee of the day will have more of a concentrated hormone that is picked up on the test.
Yesterday's test and the 2nd one today will have used urine with little or no traceable hcg hormone.
As you say you are only two days late then there won't be much yet anyway, try again first thing in the morning.