I took an iphone.. so much guilt :/?

Alright so i know it sounds bad , but i was at a camo with people i know from horse back riding and there was an i phone laying on the ground. i know whos it is, but they werent asking around for it , it wasnt working because the sim card wasnt activated, so i took it because i was planning on saying i found it on the road, i took the sim card out and deleteted everything on the phone, and i told my parents and thy find with weird it had no sim card.. idk if they are getting a little bit suspiscious or somthing :/ i really want to come clean but i dont know what to say i think my mom would loose all her respect for me and so would everyone else. help me im crying right now i have such a bad feeling in my stomache.