Help!

So I had sex on March 27th was crampy for about 2 weeks then I was fine because i was mentally freaking my self out. I was supposed to start my period yesterday and the past few days I've been iraitable then only thing ive gotten is milky stringy brownish pinkish discharge and a little bit of darker blood. Too late in the process to be implantation bleeding but still confused there are not large amounts of blood/CM. I took a pregnancy test 2 days ago and it came back negative so am I freaking out for no reason?