2 negative pregnancy tests, could i still be pregnant?

My husband and i have been trying to conceive for about a year now, and i am now 6 days late, my period was due on the 28th december, so on the 30th i did a test which was negative, i thought i would leave it a few days to see if i was just late, then on the 1st Jan my period arrived but only around a tea spoon full, which then within a day dried up to nothing, a day later i started to notice some brown and pink spotting, so on the 3rd Jan i did another pregnancy test which again proved to be negative, i still feel as though i might be pregnant though as i have very swollen and tender boobs, please can anyone advise me to whether they no what the cause could be, or if they think i am just wishful thinking?