What does it mean when your husband says he doesn't feel good or that he is tired when you know he isn't?

I asked my husband if he would help me clean up the kitchen and living room and attend to the baby so I could go to the restroom or eat or wash some dishes and the baby's bottles for three days straight and he kept saying he was tired or he was saying that he was not feeling good when I know he only acts like that when something is bothering him so I asked him was something wrong and he just said that I was over thinking it what is the deal with him.