43 days into cycle and negatives

Just wondering if anyone has experienced the same 
I'm 13 days late... We have been trying for over a year ...info have PCos but I've never missed a period and tbh they are either 3 or 4 days each way.
I've had sorry about this but have felt really wet down there ... Felt nauseous last week have had major cramping now like af is coming but nothing ... Honest it's awful I keep thinking I am coming on but all clear. The thing is have done 4 cheap Preg tests and all negative... My mum said I did so many with my first but it's nearly nine years ago really can't remember... Has anyone experienced this and got a positive ... So hard not to think about it ..... Xxx