Need some advice... have had 4 test show up with faint lines the past 3 days... they got a little darker each day... but today I started bleeding. I'm only 12dpo and my periods are due for another 3 days. Are these false positives or evaporation lines? It's really bright blood but it's not exactly a light flow. I have pcos and endometriosis. I've never had a positive reading or a faint line show up before this.