Walmart test faint line then darker

Emily

Today is expected period day. been TTC for 5 months. I took a test this morning not expecting anything. I am crampy but have been nauseated on several occasions this week. First pic is at about 2 to 3 mins. I see a faint line. Cane back at about 10 mins and it was very visible. Pregnant or evap??? it was faint to begin with. Heading to get better test today!