so confused!!

So last weekend and earlier this week I had four positive tests (one of which was a clear blue digital which said I was 1-2 weeks) which I was over the moon about. Today I went to confirm everything at the doctors and tested negative. She told me not to worry about it as the tests they have at the doctors arnt the best and don't pick up early pregnancy. To put my mind at rest I did another clear blue digital which has came back as not pregnant. I'm so confused, and totally gutted if I'm honest. I don't understand why I would get positives followed by negatives. Can anyone help?