cheating or not?

ive been with my boyfriend for 3 years now, we lived together for a year until we came to a financial problem and i moved back with my mom. we hang out just about everyday of the week were always together. i do everything for him (bring him lunch at work, always helping with his family etc) i know all his friends and family. but a month ago i found a bobby pin in his truck in the crack of the passenger seat on the floor? i asked him about it and he didnt no where it came from and i let it go..then a couple months later i lost my pendent in his truck and he tore it apart looking for it (never found) but after he searched his car i found a broken gold hoop earing i asked him if he knew what it was and he said no but maybe a part to my necklace and he found it under the seat....he denies that he nos anything about it....then recently i came to his house and we were leaving in his truck i opened the backseat door to put something back there and a package caught my eye...it was a sex stimilent!!!! and it was empty the date on the back was expired but why is it there!!! i asked him and of corse he denies it he said that earlier he helped pull his cousins van and they had trown abunch of stuff in his backseat from there van and it must be theres? the only thing i saw that they threw in his car was a rope so i dont no what to think we are always together and he dosnt have a cell so if they called his house his aunt would no i would think someone would tell me? what should i do? im starting to not trust him and its always on my mind i just dont know when he would have the time to cheat? i have lunch with him at work everyday i meet him after work all the time but i dont understand why these things keep appearing in his car