They do check before 20 weeks. At 12 weeks mine was anterior high, but at 20 it was anterior low, and covering the cervix by just a little. Your care provider will have a distance they want it to be away from the cervix for a natural delivery, and that's what they will check at 34 weeks. In 19 out of every 20 cases of LLP at 20 weeks, the placenta will move up as your lower section expands.

My antenatal midwife encouraged me to visualise the placenta moving upwards, so I did. It helped me to gain confidence, I guess, and feel in tune with my body. And it moved