+1 for the Limousine Bus.

As you'll see from the timetable link jib71 provided, the Limousine Bus departs every 15 minutes from the Haneda domestic terminals but only every hour or two from the International Terminal. For this reason, unless you are certain your arrival aligns with the single International Terminal departure at 14:40 that would work for your schedule, you absolutely need to get to one of the domestic terminals to catch the bus to Narita.