boyfriend with a high body count

Me and my boyfriend have been together for about a month and I really like him but he has a past... he used to be a little bit of a slut and really got around. He's clean but his body count is 45+ , mine is 4 (including him)... he told me it shouldn't bother me but it does. I get super insecure about having sex with him because I know he's slept with so many girls... we've also never talked about who he's slept with and what's he's done and that really bothers me... should I have him tell me everything and how do I stop feeling insecure because I know he's crazy about me but I also feel pretty crappy about it all