My last period was on Jan14 it did not come for the month of Feb so I took a pregnancy test and it came out negative. Now I'm spotting a dark brown color I don't know if this can be that I'm stress out or pregnant I'm 29years old.

You need a doctor... but yes, stress can screw with the monthly cycles... seriously, go see a doctor.

You know, pretty much the same thing happened to me. I missed/spotted in feb- then was 12 days late this month. I took tests, all negative. Well, on day 13 I got my period. It was totally normal- I think it must've just been stress (I'm currently finishing up my degree). I'm planning on seeing the doctor soon and mentioning it- but I'm not in a huge rush, I looked up this stuff and apparently it happens "often enough" to plenty of women.