Help PLEASE !!!!!

Lex

So I have a normal 28 day cycle but I am 7 days late. At the end of February I spotted pinkish blood & had sum mild cramping, I was suppose to got my cycle on March 12th but today is March 20th . I took a pregnancy test on March 15 but it showed up NEGAVTIVE idk.... can someone please help me out like what is wrong. Should I take another pregnancy test this week or what ? Here’s a picture of the pregnancy test from Sunday on March 15th.