previa, STMs?

liebekeinkrieg

At my last u/s (10w6d), I was told by the tech that my placenta was close to my cervix, but not covering it, which I had read was not really considered previa. On the lab paper for my multiple marker test, however, previa was listed under OB complications. I understand that the placenta often shifts position as the uterus grows upward, pulling it away from the cervix. My fear is that it'll reverse though, and that I will end up having to get a C-section in addition to having to be careful as my due date approaches. For STMs, were any of you told you had previa early on and it remained? I want to know the likelihood of this happening so I can prepare for the possibility of a C-section.