I am 24years old.I get my periods regularly every 28 days.now I have missed my periods for 44 days.I feel tired all day&have a backache these days.I got a negative result on my 40th day.I get a liitle whitish discharge.how can I know if I am pregnant?

You now need to do a test every few days. If 3 or 4 of them show negative on first morning urine, then you see a doctor. It's impossible to know if you are pregnant, if your period stopped because you are ill, or if it's just skipping a cycle because you are run down, maybe not eating right, or coming down with a flu or something else minor.

It's possible for test kits to show false negatives too.

If the white discharge is like cottage cheese, it's probably a yeast infection, treatable with Monistat. If it's more of a clear white and smooth and a little gluey, that is probably just normal discharge.