So doctor said I'm 1/2 dilated so not even 1 cm is there any possibility to close back up??

I don't think it can close back up, but different days and different doc interpretation.. it's not a perfect measurement.. docs use there fingers and there are different variables

Yes it can close back up. It just depends on your body.

But since your close to the end I don't think it will close back up. I was dilated 1/2 a cm at 35 weeks and at 36 weeks I was 1 cm and starting to thin out. Just ask your doctor

She said they will check me again next week so we shall see then

it's not likely to close up, but it can stay at the same dilation for a month or more even. I was 2 cm dilated for the last 6 weeks of my last pregnancy.