11 days ago I ovulated. During thos peak days I had positive pregnancy tests. Then very very faint and negative off and on. Last Monday and Friday they did blood test coming back negative. Saturday I was vomiting from stomach virus and the hospital did a blood test that was negative. Yesterday I took a hpt it was very very faint. In the picture it compares to yesterday’s opk. Today I did another hpt 11dpo and its darker than yesterday but still faint. Can anyone explain what could be happening?