I’m actually going to convert my comments to a more fully fleshed out answer. I’ve been in a very similar situation in the past, and went to visit my (then) girlfriend in the US for a period of five weeks just after finishing university, but before I’d secured a job.
The immigration officer had (or at least seemed to have, based on the questions asked) two major concerns:
If you’ve finished your degree, and you don’t have a full time job lined up, then proving that you don’t intend to do #1 is going to be tough. The best thing you can do is to make sure that you’ve booked a return ticket. Print out the confirmation from the airline/booking site, and make sure you have it with you in your hand luggage so you can show it to the immigration officer.
If you’ll be staying with your girlfriend’s parents again, having a letter from them wouldn’t hurt to prove that you have accommodation for the entire duration (since that is generally the largest cost). If you’ll be staying elsewhere (e.g. in a hotel) make sure you print out any confirmation e-mails you have as proof, though if you haven’t pre-paid for the rooms then that won’t really help alleviate any concerns over your ability to support yourself financially.
Print out a recent bank statement that shows what funds you have access to. This is to prove that you can afford to support yourself while you’re in the country. If you can’t prove that, then at least show what funds you personally have access to, and be able to explain where the rest is going to come from. Are your parents going to be able to send you money? Are your girlfriend’s parents going to cover the costs if/when you run out?
Other than that, just answer any and all questions honestly. You may very well be asked if you intend to marry her, so be prepared for that. You may not have thought about it at all yet.
Ultimately, whether there’s problems and how long it takes you to get through immigration is going to depend on the immigration officer you get, and how satisfactorily you answer their questions.
Credit:stackoverflow.com‘