Should i keep it a secret??

I've been with my husben 13 yrs and my marriage ain't perfect we had some up and downs thru out everything .lately I was feeling distant frm him didn't feel sexually attracted to him. So I had a affair with someone we did have sexual relationship and we didn't use protection now I think I'm mite be pregnant and if I am should I shut my mouth and pass it off like its my husben or should I say anything to the guy I slept with .plz no rude comments you don't know how ugly I feel about this and my stupidity took over .plz someone