period or just old blood?

HI, I?m very worried about what?s going on. In feburary I was 10 days late for my period, so I took a pregnancy test and it was negative. on the 11th (feb 25th) day I started to spot pink, which made me think that I was about to start my period. Well the faint pink spotting lasted about 2 days, then became tanish brown smelly discharge. I was surprised at this because it lasted for about 5 days (mar 3, 5th day) . It wasnt until March 4 that after intercourse that I started to bleed. So I assumed that I was really getting my period, since it felt as if I were having my period. Later I realized little clots in my discharge and whenever I would wipe. It?s March 13th right now and I?m still having discharge. Only, its dark brown resembling old blood. I considered the possibility that I was having a miscarriage, but since I?ve experienced one before I know it isn?t, I didn?t have the "heavy" cramping feeling and larger tissue clots come out. Nevertheless the discharge is dark brown and usually only takes up 60-80% of a panty liner. It doesnt flow as heavy as a period would, but it smells like old blood and sometimes I experience cramps.Also, I am nauseated some of the time, I?m experiencing a lot of bloating and some itchiness in my breast area. Along with this, I have a significant amount of weight gain, in my stomach area. Please help!! I live in Maui and the doctors here tell you its fine, and everything is okay!? But i don?t feel okay... :'(