Hi, you have to rest whenever you can and avoid too much activities like long walks, swimming and intercourse. I had it when I was pregnant. Low lying placenta makes you prone to bleeding. But don't worry much, i did not bleed and no other complications except that I had C-sect.
I'll say its better to rest more for now! Just avoid all activities. I had low lying placenta and after 2 weeks of complete bed rest (literally no activity), it moved up. :)
Sheena DL