Positive and negative pregnancy test

I’m so confused I’ve had 3+ pregnancy test come out positive and I’ve had some come back negative counting from my last menstrual which was dec.7.17 I would be 5 weeks and 4 days my expected period was on Jan 4 and was 2 days late and then I did get it it was light and only lasted 1 day. Has anyone experienced anything similar!?

This test was taken on Saturday at 12:00 am

Took a dollar store brand and it came back negative