LMP was sept 25,2010 I have aching cramping as if my period is coming on for past 2 days but nothing what do u think is going on?

You will have to wait and see. If you think pregnancy is possible, try a test. Your period may just show up a bit late.

I have taken 3 test and they have been negative and today is day 5 and nuthing still?

Try to wait another week and see what happens. Try another test at that time; if negative still, wait and see what happens next month.