My period is 21 days late. I've had cramps nausea lower back pain. The cramps and nausea have subsided some. I ve taken 2 pregnancy test could I still be pregnant. Even if the syptoms have subsided or stopped.

If you've had two negative pregnancy tests, then it's almost certain that you are not pregnant. There are lots of reasons for missing a period, and cramps and lower back pain are not really symptoms of early pregnancy.

I'd wait and see if you get your period this month. If not, talk to your doctor.