definately ring the midwife. There is a condition in pregnancy that causes nausea. Something to do with the liver or something but very rare. But check just to be sure. This is your baby so who cares if they think you are paranoid. That's what they are there for.
re: the condition, I just got over 3 days of what my doc thinks was a tummy bug (vomiting only, no runs) and he did send me for a urine test - it's kidney function apparently.

Scooby, forgot to mention that yes unfortunately some people do get a return of m/s later in pregnancy too. I hope that it's not that and that you've just had a mild bug and all is good.