I'm confused

Hi I'm a little confused I took four test two were positive with two lines , but the lines were light on the second line, an I did some research an the site said as long as u see two lines it's positive,  but took two more an those were negative, I took the day before I started my cycle an it was positive an one on the day I started my cycle it was negative... I really need a little advice I pray it's wasn't a miscarriage