Seems like everything is so perfect but could he just be using me?

There's this guy iv been seeing for acouple months. I'm 18 and he's 24. He has an 18 month old son, and I have a 12 month old daughter. He's not with his baby mom because she has issues and I'm not with my baby dad because he has issues. Everything seems like its all perfect. A few weeks ago his babymom got my number from fb or something and said he has chlamidia. I told him we can't have sex untill we both got checked and we did and everything was negative and it was his baby mom trying to get him back because she's obsessive over him. We had sex a total 4 times and last night we did it. He pulls out 5 minutes before he cums which is good and I'm on birth control. I feel everything is perfect. We get along great. I have insecuritys from my passed relationship and I didn't know I would get close to this guy. Iv said I love you to him about 3 times and didn't get it back. I regret saying it so fast. I really see us having a future and its driving me nuts cause he's older and has been with many pretty girls that are aot better looking then me. He's been a little distant lately and its bothering me a little. I don't know what to do. Could he be using me? How can I know if he's the one from me? We've been through a lot in the passed coupld months but at the end of the day I'm happy and so proud that I met and am seeing him because I never met anyone better.