Pregnancy or Anxiety Attack?

I have been having unprotected sex during the time of my ovulation and i did get my period for 3 days and it was very light. After my period on the 4th day, me and my spouse have unprotected sex. Now i am feeling dizzy, sometime headache, nausea, and bloated and cramps like i was having my period again. For the past week after my period, i have been having upset stomach and diarrhea. I did go under a bit of stress lately due to work and moving to new environment. After my spouse and I have sex, I started to noticed brownish color discharge when i go to restroom along with my own discharge. I did a home pregnancy test and it came out negative after the 6th day after my period. Is it a sign of stress and hormone changing?