Advice please

I’m 6 days late for my period, I have taken loads off test they have come back negative, I’m now like 37 days since last period. I have been so tired and been having so much pressure down there but nothing like period pains, just little old cramps. Today I went to the loo when I wiped there was brown blood there but after that nothing else through out the day. I have been having headaches and today really bad back pain. Any thoughts ?

Also took this test this morning thought I seen a vvvfl but then it disappeared.....

Just want that second line to appear so bad!!!