Had Unprotected Sex. Took Plan B Twice. Having Brown Discharge. Reason?

Hi, I had my period the 25-30 of November, 2 days after my boyfriend and I had a condom break. I took plan b about 2 hours later, because I m a worry wart . However, I also took it 2 days after because I was scared. So I had a total of 3 mg. which I know as a nursing school student is not healthy. ANWAYS, it s been about 4 days since Te second dose I took, and I had very very light brown discharge . I also check my cervix throughout my cycle and when I checked it this morning, a light red discharge showed up on me (gross I know). I was just wondering if t was due to plan b, or if it could be implantation or what?