CD 26. 9 dpo.

I had some mild cramps and what oddly felt like ovulation pain yesterday. And today I had egg white CM with some brown blood in it. Just a teny tiny little bit. My nipple have also been so sensitive, to the point where it hurts to sleep on my belly. What could this be? I usually have a 26-29 day cycle. And I ovulate on day 15-16. I have been <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a> with tests and bbt chart. Ttc for just one month now via artificial insemination. What could have this been caused from? Could it just be my period, or something pregnancy related? I took an early response pregnancy test 2 days ago and it was negative. I'm mostly concerned about the cm, blood and cramping!