Am I Pregnant? Brown Bleeding..Heat Flashes..Back Aches and Head Aches..Pregnant?

Hi im Carmen and Well My best friend and her boyfriend recently had unprotected almost two weeks ago....we both know it's a little early but just 5 or 6 day's after they had ual she started to experience some brown bleeding that lasted for about 3-6 day's, it was also lighter than most of her menstrual cycles. And then At the beginning of the week started having crazy hot flashes all day long some head aches and back pain it's been about 2 weeks now. How long should she Waite before she takes an HPT test && Can anyone help with our concerns about what's been going on. Thanks will really appreciate the help. =]