Hi there,
A low lying placenta can cause bleeding during pregnancy. Just take it easy. It is more common than you think in early pregnancy esp before 33 weeks where after it usually starts moving up.
It should not be diagnosed as a problem for natural birth before 37 weeks as it moves up a lot in later pregnancy and is usually totally clear from the cervix by full term.
I've had more than one client starting HypnoBirthing classes at 36 weeks because the placenta miraculously moved up "at the last minute".
Visualization and hypnosis can actually also help move the placenta up. We have had success in Beautifully Born with moving the placenta up by using hypnosis. Incredible.