Please relax. I do not think there is anything untowardly wrong in your health. It is common to find this kind of report on urine testing in pregnancy
You have taken the antibiotic. It should take care of your symptoms. I hope you are taking medicines for your Hypothyroidism
Previous c-section is not the cause for this neither is it due to the scar.
As I said, please relax. You will be fine soon.
Drink plenty of water.