At six months, it really could go either way. Half a year is long enough for a heart to make up its little heart brain, so there is a real possibility that your boyfriend loves you right this second. But if he hasn't said "I love you," there's really no way to tell.
So that's the answer to your question. You really can't tell.
Now that I've taken care of that, let's get to the real issue at hand. Your boyfriend either doesn't love you, loves you but is scared to say it, or is just stringing you along. Instead of spending your energy doing detective work as to which category he falls into, I recommend spending your energy enjoying the relationship and building trust.
If you and your boyfriend like each other's company, trust each other and talk intimately about your feelings and the future, those three magic words are going to come out of his mouth naturally and without any coaxing. So focus on that. Have conversations. Make plans. Be good to each other. He'll be in such a warm and comfortable place emotionally that he'll tell you he loves you if he actually loves you.
No? Then just tell him you love him and see what he does.
Either way, tell us how it works out.
Ladies, any advice or experience with getting that first "I love you" out of a guy?