Need advice

I've been dating my boy friend for three weeks and already he shows little interest in our relationship. He was vivid in seeing me and texting me the first 2 weeks then it slowly drifted to just one word responses and him making excuses every time I tried to make a date. I like him a lot, but I need to be treated like I matter. But i don't know what to do should I bring it up or just wait to see how things go?