Should I be worried? Could really use some advice.

I met my fiance in June of 2008 when I was a freshman at an American College in London and he a first year at a UK university. We were engaged in August of 2009. However, I could no longer afford to live in London so I came back to America and did a year at a local community college. Until recently, I had not seen my boyfriend for 7 months. He just left to go back home to Liverpool after staying here in America with me for 3 months. We want to fly me over in a couple weeks to visit until mid September, when my medical assistant course starts up at a technical institute in NY. However, I'm worried that since I still have a UK student visa in my passport, and have no funds (my fiance and his mother are funding my trip. His mother is providing me with a free place to stay, including meals) that I'll be denied entry even though I'll have a round trip ticket. I plan to bring some papers on my medical assisting course but I'm still worried. Does anyone have any advice?

It does seem sort of iffy, but what about some extra evidence?

Do you have a rental agreement, or a pet even?  Will you be using a credit card at all that is evidence of funds? 

I came over to visit my then boyfriend over Christmas break and I just made sure I was extra excited about my course to the IO.   

The problem is not your student visa you just have to tell the IO that you're no longer a student and wish to be admitted as a visitor. The problem is convincing them that you're a genuine visitor and you will leave on that return ticket and not try to settle in the UK without the proper visa.

Have your finace's mother write a letter stating that they are providing your accommodation, food, all living expenses and any other expenses that arise for you while you are in the UK and you should also get their most recent 3 months work of bank statements & wage slips. Bring a letter from your school stating that you are expected back for your program on xx date. I doubt you're going to be able to stay for 2 months though. Two weeks maybe, but two months especially when the only thing you have to go back to in the US is your course.

Required documentation to be allowed entry as a visitor:

This page explains what documents you should have when coming to the United Kingdom as a general visitor.

They are:

■if you are employed, a letter from your employer granting leave of absence from your job for a specified period - the letter should also say how long you have been employed by that employer, in what job(s), and when you are expected back at work;
■if you are self-employed, evidence of your business activities and financial standing;
■evidence of any property you own in your home country;
■if you are a student, a letter from your school or college stating the course you are on, its start and finish dates, and the dates of the holiday period when you intend to visit the United Kingdom;
■evidence of any family or social ties and responsibilities to return to;
■evidence of any firm travel plans you have made;
■bank statements going back over a period of several months; and
■evidence of savings available to you.

Do you have anything else in the US that ties you there...like an apartment lease or a job?

You may also should look into travel insurance, as a visitor you are not allowed to use the NHS. Even though you may have been registered at one time as a student and have an NHS number, you still are not allowed to use the NHS.

I'm coming over next week, just for 9 days, to visit my boyfriend.  We're getting "officially" engaged on that trip, and working on plans for our US wedding in November, after which I'll be applying for a settlement visa to join him in the UK.

I've got a letter from my employer stating that I am employed, in what position, and when I'll be back at work.  I've also got a copy of my apartment lease agreement.  There's also the receipt for the park rental in November.    And, of course, my return tickets. 

Being that it's a short trip, do I need to worry about additional docs, such as financial records?  Also, how do I present the documentation that I do bring?  Do I just walk up to the IO, waving it in front of me like a white flag, or should I wait for them to ask if I have any?  My boyfriend is concerned (and I am too, a bit) that having all this paperwork could seem suspicious in and of itself.

You need to show that you can fund your trip so I'd bring at least your most recent bank statement.

Don't just walk up & hand it to the IO, if they ask you for it you can show them.