Pregnant? No symptoms and had period...kinda....

Ok, I had sex with a boy 2 and a half weeks ago and i didnt have any symptoms of being pregnant. (We used a condom but the condom broke- he didnt cum but he had alot of pre-cum) About 12 days after we had sex i had light brown and pink discharge. I was freaking out because i thought it could be implantation bleeding. Well, then 5 days after that i started having alot more blood and it wasn't pink, it was RED. And the thing is I've taken many pregnancy tests up to today and they've all been a negative. Am i for sure that I'm not pregnant or do i still need to be worried?! And can a pregnancy test read negative when you're experiencing implantation bleeding?! Please Help!!