ughhhh....!!!! 😭😭😭

Today I am 9 days late I tested when I was a week late and it was a negative. Is it still possible to be pregnant??? What are some causes to be late??? Should I test when I'm 10 days late?? Should I wait to get a blood work test done till next month? I'm really confused this is my 5 month ttc. I'm so tired of seeing BFN.