hmm..to my knowledge when placenta calcifies or ages it ceases to provide nutrients to the baby.So it cld impede baby's growth.
In worst case scenario dr will recommend c section at 34 weeks.
If can wait n your situation is not so bad..the dr will induce at 37 weeks.But since you have low lying placenta..i guess it will be a c -section for you ?
dont think too much about it.As long baby is healthy i think we mummies can bear a bit of pain here n there.
Hang in there!!