What could cause brown spotting for a couple days followed by a missed period 2 weeks later.. took hpt when 1 and 2 weeks late both neg?

Get a blood test: The brown spotting you are describing sounds like implantation bleeding and the missed period 2 weeks later suggests pregnancy. A blood test is much more sensitive than a home pregnancy test. Get a blood test to find out if you are pregnant.

Depends: There are many causes for spotting and the period being thrown off. Recommend seeing a doctor with possibiliy of testing other hormone levels. Stress, other medical conditions, growths,infection.....can effect the cycle If associated with any other symptoms such as fever, chills, abdominal pain, shortness of breath, nausea, vomitting...then seek care sooner