I'm on day 23 of my period and have had several faintly positive pregnancy tests throughout the month (first one on day 13). I had a scan and there's no sign of any pregnancy... And I've also had lots of negative pregnancy tests (at the hospital I had negative pregnancy test when I had the scan so they told me not to worry). Since then I've had another faintly positive test at home...

Anyone else been in this experience? Why would I have pregnancy hormones but no pregnancy?