placenta previa

Leah • Pregnant with #2
I'm 27w4d and had a sonogram today to see if my placenta has moved away from my cervix opening. The tech wouldn't tell me anything, said she'll send the results to my dr and he'll tell me. But, she said I have to come back in 4 weeks to check again. I'm assuming this is bad news. Has this happened to anyone else?