Hello! Home pregnancy tests are usually accurate but not 100%. These tests test for B-HCG which should be being produced if you are pregnant. Your symptoms are seen in early pregnancy but can also be with other conditions. There are 2 tests that would be most helpful for determining if you were pregnant. One is a blood test that actually measures the amount of Hcg in your body, it results as a number, not positive or negative. The other would be an U/S to look at your uterus and to determine if there is a fetus (baby) there. If these are negative, then it is possible you could be having some alterations or abnormalities in your hormones (estrogen or progesterone) making your periods irregular and mimicking pregnancy symptoms or there are other issues such as thyroid problems that could also present with these symptoms. Good luck and take care