Pregnant?

I have a son already and my first symptoms were just sore breasts. And I found out I was pregnant with him a week before my missed period. My husband and I have been trying for a few months now to have our second one. According to glow and ovulation test my ovulation day was dec 2. But my period normally starts around the 9th and according to glow it doesn't start till the 17th. However I have been very emotional, and very nauseous, tired and frequent urination mostly during the night. So my question is.... Could I be pregnant and if so is it possible to have symptoms this early? Or could it be something else?