I was prescribed celphalexin 500mg to take 3 times a day. I have a major phobia of taking any medicine for fear of having a serious reaction to it. Ive never had a serious reaction to any drug before but still have the fear of it happening. I took my first dose yesterday and nothing bad happened. But, after reading about the possibilities of what COULD happen, ( I read that a person may not have a reaction during the first dose but could happen during the next dose) I am now afraid to take the second dose. Help!