Zofran literally got me thru my first trimester...I was able to function without it around 16 weeks. Now at 24+5 I only get nauseous when I wait to long to eat or something doesn't agree with me.
Zofran is a miracle worker.. Ask your doctor
I have been fortunate to not experience morning sickness with my 11 yr old or now at almost 8 weeks. Maybe if it continues you can ask for compizine or another anti nausea medice that worked for me when I had cancer.