Placenta previa

I was diagnosed with placenta previa at 19 weeks am currently 26 weeks and i have slight contractions a week ago and doctor told me my placenta is still low covering have my cervix, but i saw my OB Wendesday and said  after my next appt April 8 will determine if i should go csection because i do get alot of pressure down their like something going to come out and beside when i urine i have. White discharge that look like little cottin balls is this normal or should i be concern ?