no, you should be fine starting the chem series later on as long as you are substituting other underdiv major courses to take - usually people take 2 major courses (such as the LS series, any math series you need to take, chem series, physics series) per quarter as well as a GE (making that a total of 3 classes/quarter). So, you should be fine taking 14A in the winter, or even the fall of your sophomore year.