What Causes Light Periods,nausea,dizziness,loss Of Apetite And Soreness In Breast?

My husband and I are trying to concieve. My periord was 4 days late then I started bleeding. The bleeding only lasted about 2 days it started light got heavy then ended light. I usually have clotting and this time I had none and my normal period lasts usually 5 days. Since my period was late I took several HPT which all came back positive. After the period I took one and it came back negative. The symtopms I am having are nausea ( no vomiting) dizziness/light headedness, loss of apetite, my breats are larger and more firm to the touch. Could I possibly be pregnant?