everything i have found while looking it up for you does not show any risks to pregnant women/fetus, as MRI's do not emit radiation.....but you should still ask your dr, as he'll be able to make sure....however, webmd, and several university hospitals are on record stating there have been to teratogens(sp?), introduced to the fetus during an MRI because there was no presence of radiation during an mri.....
congrats on your pregnancy!
I think it is probably fine. I would just make an appt. with your doctor as soon as you can and see what he/she says about it. It was so very early then. So, I really believe that it will be okay.