I am so confused

Faith

So I didn't have a period all of September and now I am 15 days late

I am nauseous, have cramps, back ache, heartburn

So I was like okay that's weird so I took a digital clear blue and I took two and both showed the book symbol

So I look at the test and the book is on both but if you press on the screen or if you have a certain way you see not pregnant

Should I disregard what it says and test again?????