You need to satisfy Homeland that you are doing exactly what you say you are, remember you are not entitled entry and you have to meet all the requirements of a visitor.
As already stated you need to take as much evidence as possible with you to present to the immigration officials. This includes flight information, evidence you can afford the tickets and support yourself with access to funds (wage slips, bank statements etc). You need to be able to explain why you are able to take so much time off from work as a week off after every 3 or 4 is quite a lot (nice for some eh!). Maybe carry your business card or employment contract?
The problem you have is that the more time you spend in the States the higher the risk you are from an immigration point of view as you may be tempted to overstay/work illegally. This obviously isn't the case however so you need to be able to prove the contrary.
Make sure you get your passport stamped when leaving the States as building up good immigration history in your passport will further show that you are sticking the the rules. If for some reason you don't get your passport stamped on the way out then ask a UK Immigration Officer to do so when you get back home.
None of this will guarantee you entry however, but as long as you do the above I don't see why you should have any problems.
Hope this helps!