Problems w/ Boyfriend.?

Alright, I have been w/ my boyfriend for about a year. & I wouldn't say that I'm insecure when it comes to him around other women. It's just this one girl named "Jasmine" he was known her for a while & she wants to be with him. & he swears up & down that she has moved on & they are just friends. Well, about 2weeks ago.He went over her house & they talked for a bit.So he says. I don't know If I'm jealous,I wouldn't call It jealously by a long shot. I just think that he should leave this girl alone & I'm in Arkansas & he's in Texas. I just recently moved out her because I started attending college.I really do love & cherish this man.I just don't know If I can get past this. There has been numerous times where he's seen jasmine. Going to church w/ her,etc. Like I told my bf, I have NO PROBLEM w/ him having female friends,just as long as I know that everything is strictly platonic. And every-time I some much mention her name/He jumps crazy. I believe he's doing something w/ her. I'm trying my best to trust him,but he gives me reasons not too. PLEASE HELP