Placenta leak!!😣😢

Im curently 29 weeks pregnant, I went to my dr.s apt this morning and found out I have a small Placenta leak The dr found it on my 20 week ultrasound but is just now telling me,I guess she thought she mentioned it to me already but never did...I have an ultrasound in two days to see how it's doing. Now I'm really freaking out!! Has anybody had any experience with kind of situation?