The major drawback with home pregnancy test (i assume,you had taken a home pregnancy test kit) is that if a test produces a false negative result and you actually are pregnant, you may postpone seeing a practitioner and taking appropriate care of yourself. So if you use such a test,keep in mind that it is not designed to take place of a consultation with, and examination by, a medical professional. Medical follow-up to the test is essential.Since your test is negative and you periods are still due, you have to see a doctor, and then need to find out why.
It looks like a pregnancy to me, but still until the issue is explored by the doctor you should "act pregnant",until you know for sure that you're not. Possible causes for the absence of periods are - travel,fatigue,stress,fear of pregnancy,hormonal problems,illeness,going off pill,extreme weight gain or loss,breastfeeding.
Possible signs of pregnancy are - 1. Absence of menstruation (following conception), 2. morning sickness-with or without vomiting (2-8 weeks aftr conception), 3. frequent urination (as early as 2-3 weeks), 4.Tingling,tender,swollen breasts (as early as a few days after conception).
P.S - You can have all of the signs and symptoms of early pregnancy and not be pregnant.Or you can have only a few of them and be very definitely pregnant.
When you take the Home pregnancy test kit next,keep the following things in mind (you may be aware of all this,but still,just in case)-
1- Read the directions for the test throughly before you use it (even if you've used it, or another test, in the past)Then reread them,just to be sure.
2- Have an easy-to-read clock,watch,or timer ready so that you can time the test precisely.
3- Be sure containers, dipsticks, or any other equipment to be used with the test are clean when you begin the test.Don't reuse these if you want to try again.
4- If a waiting period is required,place the sample on a flat surface away from the heat and in a place where it won't be disturbed.
5- Read the test after recommended waiting period; not waiting long enough--or waiting too long--can affect the result.
6- If the kit you purchased contains a second kit, wait at least a few days before trying a retest.
Good luck..and please go to the doctor as early as possible....Regards.