Bad sex drive or is something wrong with me?

My boyfriend and I have been together for about three years (three years in 4 weeks if it matters) and we've been intimate for a year and a half I think. At first we did like every couple and were crazy about the intamacy and over time it got to the usual amount of most couples I think. However for the past couple weeks I find myself almost never in the mood. Mt boyfriend is a guy and obviously wants to have sex but I'm rarely turned on now. Should we try something new? Is it my sex drive? Could it be all the stress? Is something wrong with me? I love him and find him attractive but I'm struggling to be in the mood. Please help if you can.