Late on by 53 day

Hi everyone

I am late on my peroide and I have done a test and it come back negative Ii was wondering could I still be pregnant as I have been feeling sick my breasts are sore and I have been getting cramps and pulling sensation everyday some times all day..

I have been to the doctor and they have told me to go and do another test because they don't do then and still got a negative result do tests stop working over a periode of time becuase my last af was 24 July this year any ideas x