Becoming Distant After Sex?

My boyfriend & I have been together for 1 month. This past weekend, we spent time together, & we gave each other oral sex for the first time in our relationship. This was our first sexual act together in this relationship. When he went back home (he lives about an hour or two away from me), we texted each other as usual, but I noticed that he was responding to everything I was saying with either one word or very, very short sentences. We both consented to everything we did, & yesterday, he never texted me back after 2:50 PM. I texted him 4 times throughput the day yesterday, & even sent him a good morning text this morning, & he never responded, but happened to look at my other social media posts. I trust him, but when he does little stuff like not texting me back for hours or until the next day, I start to get paranoid. Our relationship is good, but I feel like after this weekend, he seems a bit distant. He's the only person I've ever opened up my body to (sexually), & now that he hasn't really been talking to me, I'm starting to feel as if I've done something wrong, even though we both wanted it. I'm thinking of asking him later what's going on & why does he seem so distant now. I don't want to regret anything, but I've never been through this before & I'm trying not to cry about the situation. We're both in our early 20s. I don't know what to do at all.