Baby growth during 7 months pregnancy.

I am 7 months pregnant and my LMP date is may 4th 2017. -On October 4th when I went for scan my EDD date was given as 11th February 2018 -on November 6th when I went for scan my EDD date was given as 18th February 2018 and on the same day Dr suggested me to go for stitches as my cervical length was 1.9 cms and so I have gone through stitches on the same day. ( 25 weeks 1 day) -on December 2nd when I went for the scan my EDD date was given as 25th February 2018. (27 weeks 6 days) My question is, as per the above data it is observed that the EDD date has been moved up from 11th February 2018 to 25th February 2018. Is it normal or is there any problem in my pregnancy Please advise what precautions should be taken to ensure my baby growth is normal.