I had a very similar case to you and I hope my story can help you.
I'm a 23yo male, and had sex with a Thai prostitute in Koh Samui 18 months ago (Jan 2010). I fingered her, gave her unprotected oral(Stupid stupid me!!!), and she gave me oral and then we ******. I'm not sure if I wore a condom or not, I was that blind drunk! So drunk that I couldn't keep it up and had to stop(Thank goodness).
The very next day I started experiencing symptoms: muscle pain, night sweats, loss of appetite, fatigue, lethargy, then 3 months later I had diarrhea for 4 days and then my tongue went white and my right leg started losing hair, got a scar and went sort of red.
I was convinced that I had contracted HIV and was so scared I didn't know what to do. I thought about my funeral, suicide, how I couldn't carry on the family name, you name it! I cried, I was angry and then became depressed and very anxious. My family and housemates noted me becoming a bit miserable and my sister noticed my white tongue, but I still kept it a secret from EVERYONE!
It was only last week that I decided to get the test done, to confirm what I already knew. Then YESTERDAY (2nd Sep 2011) I picked up my results. I had to wait for 10mins for the doctor at the clinic and when he took me into his room he looked nervous, I was soo scared. Then he sat me down (All yesterday) and told me all the results came back negative! NEGATIVE!! I was negative for all tests done: HIV, Hep, syphillis and chylamidia.
It was such a relief, although today, I don't feel any different, I still feel anxious and miserable, and I don't know why. I think all those bad thoughts for the past 18 months have really ingrained themselves into me, and now I want to start feeling normal again. I can't explain any of the symptoms, I'm hoping they were due to anxiety and if they don't improve I'm going to see my GP.
As for you mate, try not to worry about it. As I said, I was CONVINCED I had it, but was still negative, even with all those symptoms. Don't go trolling through the internet for symptome etc. like I did, just go and GET TESTED and REMOVE ALL DOUBT. By the sounds of it you don't even sound symptomatic, but if you are it doesn't mean ANYTHING!
I really hope this helps mate and best of luck, I'm sure you'll be fine.
Teak answered the first part
Second How nervous should you be?
this is all up to you. But my advise is this
A. do not have unprotected sex again untill you know your test results.
B. there are good odds you had no exposure even with unprotected sex so just wait the 3 months.
C. dont go looking for symptoms and dont research anything. for the love of god please dont do this.
D Take care of yourself and keep moving. Life goes on no matter what.
Take care
You can obtain your conclusive test 3 months post exposure.