My OB prescribed me Zofran. And he is so cautious, he didn't even let me take benedryl in the first trimester. DH is a pharmacist and he allowed me to take the Zofran. Hubby is so cautious when I'm pregnant, he wouldn't let me take Halls because of the menthol. So, as far as meds go, it's pretty safe.
I found the Zofran did leave me still nauseous, but also did stop the vomiting. Like you, I only took it when I felt ill.