I need help!

My husband and I have been ttc for over two years now. My period was due this past Sunday, and I have yet to get it. I took three pregnancy tests that came up negative, and even went in for a blood test and that was also negative. It felt like someone was playing a sick joke on us. Now, I still have not had my period, but I have had light spotting. Brown, pinkish seldom through the day, and once in a while a darker brown/red color. This is very unusual for me. I usually get my period on time and I'm familiar with the flow and everything. I'm just so weirded out at this point...idk what is going on with my body. Could I still be pregnant? Could this very very light spotting be considered my period? Helppppp please