Additional to the lack of gender and ethnic diversity, the attrition rate among Physics and Engineering undergraduates is as high as 40%. Considering the impact of STEM gateway course on students' choice of major, we investigated the association between students' Expectancy-Value beliefs at the beginning of the class with their intent to persist in Physics by the end of an introductory Physics class using a sample (N = 337) diverse in sociodemographic composition. Motivational profiles predicted students' intent to continue a career in Physics and an increase in their certainty about their choice but did not predict a decrease in such certainty. First-generation college students and Latino/a were more likely to become less certain by the end of class.