Showing as pregnant but fearing the worst

I was taking injections of suprecur as the beginning of my ivf cycle as I had been trying to get pregnant for 2 and a half years unsuccessfully.

I was told ivf would help me as I have always suffered from a thin lining. I had my last period on 21st april and I had an appointment on Friday last week to scan me to see if I was ready to start my menopur injections but they said ironically my lining was 6.2mm which was thicker than it has been. They told me to come back in a week

I took a pregnancy test and it showed a very faint line which I assumed was an indent and waited for my period.

On Sunday I took another test which showed dates and it showed me as being 1-2 weeks which would not make sense as I should be 5 weeks so the test should show as 3 weeks surely?

Has anyone else experienced this?

I feel so excited but confused as well, that this baby will not survive or that the tests are not right.