On July 28th, I had two days of discharge and then 4 days of a period. Normally I go all 7 days with a full period. Then, on the 8th of August, I had 4 days of period and then stopped. Since my last period in July, my breasts have been really tender, mainly around the nipple area. I have taken two pregnancy tests, and both come back negative. My husband and I have had sex unprotected many times during this period. Could I be pregnant, or is this just an unusual month?