Very faint bleeding this morning

I had just a tiny bit of blood this morning, but i'm about 33 weeks and this is my first bleed since I've been diagnosed with complete placenta previa. The doctor told me to stay off of my feet and relax today, and if it gets worse, to call. I haven't had an u/s since I was 20 weeks, so I was really thinking that maybe the placenta had moved up and out of the way, but now this little bleed makes me think there has been no progress. I'm supposed to get another u/s next week, so maybe it will move by then? I highly doubt that's possible though!