If her period doesn't come between now and 20. i would test. good luck. and to avoid getting pregnant that is a really silly question to ask. unprotected sex is how people get pregnant so either don't have sex. and use condom and birth control. good luck
People vomit for dozens of different reasons. She could be sick, might have eaten something that didn't agree with her, it could be nerves, or might be related to pregnancy. Only way to know is to test.
Traveling can cause sickness.if you mean she was on her travels.could be a number of things you really wont know unless she takes a test.if she has a regular cycle of 28 days.then she would be due her period around the 17th,if she dont get it,then maybe take a pregnancy test.
Today just before 2 hrs she did vomitting but she was travelling from todays..what could be the reason..She is extremly worried?..
Like posted above, it's very possible. There is no way to avoid pregnancy now. You should use protection if you don't want children. Wait to see if her period comes and if it's a week late or more have her test with first morning urine. You stated she's due on the 15th, but if her last came on the 20th it could very well come on the 20th this month as well.