I am in my 18th week of pregnancy. During the 17th week ultrascan, report shows that I am having low lying placenta 2 cm away from internal os with grade 0 maturity. I am having pain in pelvic bone, pubic bone, thighs due to which I feel difficulty in walking. 1. Is this pain because of low lying placenta 2. Will the placenta go upwards as pregnancy progresses. 3. What precautions I have to take at this period of time for the above said condition, like do I have to take complete bed rest, can not I climb stairs etc.