In the Second trimester lost mucus plug, how often does it regenerate/grow back does it take 24-72 hrs or is it a long process nearing 3 weeks?

Plug loss needs exam. Losing mucus plug in the second trimester requires assessment by the doctor. It may represent painless cervical dilatation with risk of preterm labor or even delivery. Very often a "perceived loss of mucus plug" is increased volume of normal vaginal discharge which is very common in pregnancy.