i am 17 in a long term relationship i have only had a sexualy active relationship with two people and they go for monthley checkups to see if they have any STD's and two weeks ago i had sex the next morning i got a dark brown discharge and cramping, i usualy get a realy bad cramp during the first 24 hours but not lasting a whole two weeks the discharge is realy heavy and looks a lot like waterd down blood i have been seaching to see what it could be im a bit worried as about a month ago i was due my period but never got it i thought this may be because i just got an inplantation/ rod as this can make your period move about a little.
please help it is realy sore and anoying.