hello,

U have not mentioned whether u had taken any contraceptive measure??
At which day after your last period you had sex??

U already have used pregnancy test which is negative.
Let me tell you, positive results of those tests are more significant than negative.

Failure to follow the instructions properly, done the test too early may resulted in negative result inspite of there is pregnancy.

i advice you to wait for more 2 or 3 days, if periods dont come , consult gynaecologist.

If you have tested your urine for pregnancy and found it to be negative, there is less cause to worry but still get yourself retested after another week if you do not still get your periods. If it is not due to pregnancy, you need not worry. Such a situation is often seen in young patients like you. The cause needs to be investigated and treated (if applicable). Please visit a gynecologist and get a ultrasonography of lower abdomen done to evaluate that nothing else is wrong.
There is no homemade solution to give you periods and neither would I suggest you for one.