It sounds like you are fine. While the placenta doesn't move, it is going to change position relative to the cervix as you progress so it probably will end up in a slightly different spot later.
The placenta was partially on top of my cervix early on. But near the end of my pregnancy it was far enough away so that previa wasn't a concern. My understanding is that this is very common, so you shouldn't worry about previa until much later in the pregnancy.
Hope everything is going well for the 2 of you!
