All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If you vomited unintentionally then your vomiting does not affect your fasting and your fasting is correct.
However, if you deliberately vomited then your fasting is void and in this case you have to make up every day during which you vomited intentionally. The Prophet said: "If a person is forced to vomit he does not have to make it up but if he vomits intentionally, he has to make up that day." [At-Tirmithi].
Finally we draw your attention to two matters:
Firstly, if you are in doubt about the number of days during which you vomited, you have to be sure and opt for the greater number of days you think you vomited.
Secondly, Islam has permitted a pregnant woman to break the fast if fasting affects her health or the health of the foetus, and she has to make up any day she breaks the fast.
Allaah knows best.