What Causes Irregular Periods And Whitish Discharge?

my period is delayed for 18 days now and i dont have any pms symptoms which i always have in the past,I have always had a regular period.I had an eggwhite like discharge with a streak of pink blood last month in the middle of my cycle first time i experienced it as far as i can remember.I had 2 periods in one month, the latest it lasted 5 days and it was heavy,the first one was just light and just some sort of brownish color blood not really bright red but and it lasted for 2 weeks on and off.Im 43 yrs old,i feel like i had a slight fever now...