Hello, I have gone through your query and understood the concern. If you have always been regular with your cycles, are sexually active and have a missed period now, you can go for a HPT with a fresh early morning sample of urine. The online pregnancy tests derive the answer based on the information furnished. Most often useful, the chances of failure are also high if proper information is not submitted. Your symptoms are indeed, suggestive of a very early pregnancy, but, clinical confirmation is mandatory. You can also o for the blood test and follow it up with a trans-vaginal sonogram to plan further management. Hope your query has been clarified. Take care.