At what point does your man's "girl pals" become a threat?

In a new relationship (almost 2 months) and my bf is always hanging out with his gal pals or mentioning their names in every other conversation. Ex: Last night I called to say hi and asked what he was up to: "Hanging out with my friend Jennifer and watching sports center." I'm trying to stay cool about it, but starting to feel a twinge of jealously. Am I overreacting?