Should I consider this my period?

I am on a 28 day cycle, and had a regular period January 26 - 31. However this month has been a little screwy. I have been spotting/lightly bleeding since Fri Feb 19. It will come and go. Usually it comes lasts for an hour or so and then disappears until the next day. Its red with some small clots sorry TMI. My husband and I are ttc so we have had unprotected . My are tender, I am tired, thirsty, moody, and can smell almost everything, and I noticed today that my areolas are getting darker. I took a pregnancy test on the 22 of this month, it was negative. Could I still be pregnant, and if so should I be worried about the bleeding/small clots?