Is sexting cheating? I need help.

I’m 20 and married, and i used to go on these Omegle website to talk to strangers for fun. One day my husband found a couple pictures of a girl’s body in some porn site that it totally looks like mine but its was very odd bc in the background of the picture doesnt look familiar to me, i had never went to anyone’s houses to do those kind of stuff. please help me, i told my husband that girl wasnt me but should i tell him that i used to went to those websites??