Confused on being pregnant!!!!?

hi ya im confused as if im pregnant or not, me and my partner are trying for a baby, my periods run like clockwork, but this mth i havent had 1 but slight brown discharge and period cramping, im suffering with and nipple tenderness, feeling sick, lower back pain plus bloating, for 2 days now everytime i go loo and wipe myself i notice pink like blood on tissue. been doctors and he tested me but it was neg. am i? or aint i? this wud b my 2nd pregnancy.