Oh, this is such a scary thought, I completely get why you'd ask this. The thing is, usually, a stroke happens suddenly. There aren't really 'symptoms before it happens' in the way you might think of a cold developing. Sometimes, though, people might have a TIA (mini-stroke) which has stroke-like symptoms that resolve quickly, but that IS a stroke in itself, just a temporary one, and a huge warning sign for a bigger one. So, if any symptoms appear, no matter how brief, get medical help immediately.