Pregnancy related. Go. plz help!

Hi doc, my lmp was on 10 July 2018 that means my pregnancy is 27 weeks 1 day long and on 15 Jan 2019 I have my us according to which my baby weight is 1.2 kg and if I am not wrong it  means that his gestational age is almost 29 weeks. Actually my doc told me that my amniotic fluid ranges 6-7 cm it is on lower side. I have apla syndrome and earlier I was taking heparin 5000 iu in a day but from yesterday onwards my doc increased it to 10000 iu and I have increased my liquid intake also , will it  help me in increasing amniotic fluid.and I  wanted to ask that is my baby overweight and if yes than is it ok as my fluid is low it might be possible that I have premature delivery. And with fluid 6-7 cm could you plz tell me how long can my pregnancy go.plz help