Softening of cervix!

Hello ladies, I’m 36 weeks and 3 days and had disgusting pain in my lower back and legs and so I went to my dr. She told me earlier that I’m carrying baby low.

Yesterday she checked me internally and said that cervix has started softening 😱 went for an ultrasound that said my baby is in vertex position.

I’m so afraid to have a baby just at 36 weeks, my doctor said that the baby is perfect and ready for birth weighting 5lbs 3oz but I think it’s less.

Now I have two questions in my mind-

1- When will labor start if my cervix has started softening?

2- Is my baby weight less or sufficient?

Thanks in advance for your help.