Lonely..

So my Husband has been acting weird lately ..he used to always love being around me Cuddling spending time and sex was like an everyday thing but recently he's been distant and pushing me away when I go to randomly hug him or sit and cuddle next to him. I don't want to jump to conclusions and think that there might be someone else because he says he's really tired from work (he's a construction worker) but I'm starting to take it really personal because things just aren't the same ..any suggestions?