Welcome to HCM
Please do not worry about fever as you are pregnant,Every fever is not Typhoid and such test like widal do not come positive in first week and if clinically suspected strongly then a Blood culture
is required to diagnose typhoid,and correlate clinically.
fever due to Urinary tract infection
is common or a viral fever
may be there.
Just take normal diet if you have nausea and vomiting
try to take small meals but frequently.
Water should be potable save your self from mosquito bites use mosquito nets.
Keep very good hygiene .
Take balanced diet fresh fruits,green vegetables and dairy products.
Any supplementation of Calcium and Iron prescribed to you.
Hope your fever will settle in few days .
Just take good care
Best of Luck to you.