Hi, as you are pregnant, and your cough is still persisting, and already you have taken many antibiotics after blood tests etc. So this seems to be allergic cough
. I would suggest you to avoid curd, buttermilk, banana etc. Drink warm water, ginger tea, hot soups at frequent intervals. Warm saline gargle twice a day will also be helpful. You can also try ayurvedic cough syrup like Honitus 10ML Three times daily. Get well soon.