Confused

So bf and I talked everything out and everything went back to normal. We started to hang out more, talk on phone and text 24/7 like we normally would. We hung out on Wednesday but the following days, he wouldn't text me much. Which I understand, people get busy and stuff happens. But it's happened for three days straight. I know on Friday that he said he was having a bad day but that everything was fine. I told him that if he needs to talk about anything, that I'm here for him. Yesterday, he didn't reply until 5 pm. Should I ask him if anything is wrong (or is that overthinking and over bearing) or should I let things play out themselves?