dental X-rays while pregnant

I'm four months pregnant and just went to the dentist. They had to have me fax over a slip saying it's OK for the dentist to see me while pregnant. And so they did the dental exam which included the x-rays. And while getting the x-rays I passed out. Is that normal? I have 6 cavities and they schedules me an appt to fill one of them next week.. will that be ok too?