Hi I'm 18 years old. My last period was on July 21, 2007. Since then I haven't gotten it, but I took a pregnancy test and it came out negative. Could I still be pregnant or is something else wrong. I am really worried, please help.
If you feel you are at risk for an accidental pregnancy and are past the 120 hour mark for emergency contraception, you can wait until 10 days after the incident or after the first day your period is late to take a pregnancy test.
It is much more likely to have a false negative pregnancy test than to have a false positive. By that I mean if it's negative, you can and should test again in a few days to confirm. But if the test is positive, it's pretty darn likely that you really are pregnant.
Make sure you follow the directions closely. It is best to use really concentrated urine for a home pregnancy test. Take the test first thing in the morning, right when you get up and head to the toilet. If your urine is too dilute, then there might not be enough hormone (human chorionic gonadotrophin, hCG) to show a positive test.
If you really are not pregnant, and your period is still missing, consider other factors: are you stressing over the pregnancy scare? Are you dieting? Do you have an eating disorder? Have you need exercising too hard? Are you ill? Are you stressed from other stuff? All of these things can affect your cycles. If your menstrual cycles tend to be irregular, see your doctor for an examination.