how long for changes to show in mri?

Hi, I am a 32yo female with a young family and I know I am not mad.....I had a ? stroke ? 16 days ago. Drs seem to disagree on my diagnosis as they are "not consistant". My CT and MRI were both normal. I did have blood tests done but I have not been told anything so I have assumed they are normal. So to begin with they said TIA, one dr suggested functional disorder another MS. I have been prescibed asprin and lipitor. My speech was very slurred and slow and stuttery, my voice even sounded deeper to begin with, now my speech has improved  a few issues but almost to back to normal. I still have left sided weakness, terrible balance, my left eye/side of my face had dropped but has now corrected. I am finding the strangest things difficult like not understanding when people spell out words or being able to follow several instructions at once. So something is definetly wrong. The ct scan was done only a few hours after and the MRI 5 days later.

Is it possible for it to have been and gone in that time or perhaps just had not showed up yet?

Does anyone have any ideas or knowledge on this
Cheers