26 week preg but belly size is large.

Good evng Had met gynae today ,she told my stomach size looks like 30 week pregnant ,howeber im 26,( im 26 weeks acc to usg n 29 acc to lmp),she says it seems that water is more in ur stomach.my level 2 was perfect (23/4/19),which was ok. She scheuled usg in week 28 to check water level and i was told it might be due2 sugar,however RBS cames 98-100 check thrice till level 2.Also advised glucose tolerance test. Im very scared until my usg happens,even i was not able to ask any ques with gynae ,i was so tensed. Is this situation critical. Due 2 leg n feet pain shelcal xt twice a day,cobadex czs od,livogen-z odeltroxin50 Weight b4 pregnancy 71,now 82. My weight increased 3 kg in last 15 days after starting shelcal xt n cobadex czs ,do they inc weight. Todays bp 80/120.