Hello, I'm a self appointed expert, having suffered twice.
With DD1, all the advice I was given was that if I get any bleeding, call the labour ward. I knew 3 other people who had placenta praevia, and all 3 had a planned CS at 38 weeks, I assumed I would be the same....At 33.5 weeks I passed an enormous clot, called labour ward, was admitted, until DD born at 37.5 weeks. I would have been released, but suffered intermittent bleeding from admission onwards.
With DD2, I was told at 21 weeks the placenta was low, so immediately packed my hospital bag. The advice I received was very different. They tried to get a consultant to see me immediately, but ended up the following week. Instructions were: no sex, no flying (bang went the hen weekend in Krakow) and loads more I can't remember. I was admitted at 24 weeks, 26 weeks, 31 weeks, three times at 33 weeks and then kept in. Emergency section at 36+1. At various times I could not be on my own at all (very frustrating and did lead to a paddy!), could not be more than 20 minutes from the hospital......
My advice would be, have a bag packed just in case, keep your notes close to hand.
Remember, none of my friends had any problems, but ask your MW for advice.