Was pregnant now I'm not?

I am heartbroken. I cannot explain it. I started my period last night (8/9)....how is this possible?

Was I pregnant then lost my baby? Can anyone help explain please?

I took 4 home tests on Monday (8/7) when my AF was due and they were positive, different brands. I went to see my doctor yesterday (8/8) and their tests came back negative. More false positive home tests? I've had two before this one.

Please help. I feel like I won't sleep without some explanation.