We have been trying to get pregnant for some time now. I was suppose to have my period 2 1/2 weeks ago. I have been experiencing frequent nausea, urination, headaches, have fuller, sensitive breasts, back aches and more heavy milky vaginal discharge.

I took a home pregnancy test one day after I missed my period but it was negative.
The last three days I have been experiencing light spotting and bleeding but only after urination and then again nothing.

What can cause the symptoms I am experiencing if I am not pregnant and should I be concerned because of the light spotting I am experiencing 2 and a 1/2 weeks after missing my period?