Is an aching uterus a sign of early pregnancy?

Today is 10 days past ovulation, and have been experiencing an aching (feeling heavy) uterus. Also experiencing weird cramps and twinges (not like AF cramps, completely different). since 5 days past ovulation. have not been sore (usually I have killer s) until today, now they are aching also, more in the nipple area. Has anyone had these experiences and been pregnant? I caved today and did a Pregnancy test, but it was negative, but it is still early yet. Also I am charting and fertility friend has said it is triphasic, which hasn't happened in the 4 months I have been charting! Any advice or stories would be great right now......