Vvfl followed by negative

Louise
Has any ladies had a very very very almost unseeable faint line on a pregnancy test and then the next day followed by a negative? I'm really confused and I don't know what to think... The last two years I have never ever had any glimmer of a positive until yesterday. Hubby has had a reversal re-do in June and only bd twice last week so I thought I would be out this month. But then after yesterday I really don't know what to think. I have a few symptoms but nothing much unusual from what I experience with af. I will be due af on Monday or Tuesday next week. Any advice would be lovely. Thanks