Hello, I would be happy to help.
You are vomiting
because this is a common symptom of pregnancy
beginning at about 5-6 weeks.
The cause of the rash is uncertain, but you can treat it with some topical hydrocortisone cream
An allergic reaction
would not be so localized to one spot on one side of your body - it is likely not the Pregvit.
I hope this helps!