Don't be embarrassed about asking those types of questions, first of all!
You didn't say whether or not you knew that the client had HIV? I don't know if that's info that you're privy to as a massage therapist, but either way, if you're questioning your own status, it is very easy to be tested. As SJoe mentioned, there are home kits available at the drugstore, or you can contact your local AIDS task force, where they will probably test you for free. In this area, the task force offers free, anonymous testing (you're assigned a number when you call to make the appointment) with oral swabs and/or blood draws.
If the patient did have HIV, it is technically possible for you to have gotten it from that blood if the blood was wet or fresh and if you had open hangnails or ripped cuticles or cuts on your fingertips where you rubbed over it. It sounds unlikely, considering your description of the situation, but really, there's no sense in worrying or fretting about it when you could simply go ahead and get tested and find out for sure, right?
I hope this isn't the reason you haven't slept for a few days! Make the appointment and get yourself some rest!
And...now you know that it *is* possible for transmission to occur, though probably highly unlikely, so you should start practicing stringent infection control techniques with your clients if you aren't already! And take care of your skin- it's your number one barrier!! Good luck. ;>)