Good day

I last saw my period on the 16th of December 2012, on the 30th of December 2012 I started getting nipple pains and headaches so I took first response pregnancy test on the 1st January 2013 and it was negative. On the 31st December 2012 my boyfriend and I had unprotected sex to which ejaculation occur in my vagina At this point still getting of nipple pains and headaches. What does this say or mean?

It's too early to take a pregnancy test. You need to wait until 14 days after a missed period.