I think i am pregnant?

Considering all of your symptoms, especially the darkening of the areolas, you are most likely pregnant. Since it has only been a little over two weeks since the sex that most likely resulted in pregnancy, it might be too soon to test because every woman's hormone levels are different. Some women can get a positive test before their missed period, and some don't get one until weeks, or months in some cases, later. HCG, the pregnancy hormone that tests detect, does not always make it into your urine quickly, so you might be getting false negatives. I suggest you see a doctor or go to a clinic for a quantitative, not qualitative, blood test. If you are pregnant, your blood should contain more HCG than normal, and HCG shows up faster in your blood than it does in your urine. Quantitative tests measure the exact amount of HCG in your blood whereas qualitative tests detect a minimum amount (usually 25 IU/mL of HCG, the same amount that sensitive urine tests detect). Since it is still so early in your pregnancy (if indeed you are pregnant), your blood and thus your urine might not even contain 25 IU/mL of HCG yet, so that is why you might get false negatives on both urine tests and qualitative blood tests. However, on quantitative tests, as long as you have at least 5 IU/mL of HCG in your system, you are considered pregnant. I hope this helps and good luck to you!