I'm sure this is a very stressful time for you. An unplanned pregnancy, and then this scare. Please disregard the above comments from balotelli, as we're not here on this forum to judge, or give moral advice.
The doctor was absolutely right, you cannot even compare the statistics of becoming pregnant versus transmission of HIV, it's night and day different.
The odds really ARE in your favor. We don't typically get into detailed answers about "odds" on this forum, but just generally speaking, there's definitely a significantly greater chance that you WON'T be infected versus that you'll end up +.
A DUO test at 4 weeks after your LAST unprotected exposure with your BF will be very very reassuring, and a good indication of your status. We adhere to the official guidelines, and will recommend that you retest at 3 months post exposure as well, for a definitive result. That's more or less a formality at this point. If the DUO is negative, you can breathe a huge sigh of relief.
Try to keep yourself busy and not over think this too much, as it will fuel your anxiety.
Off topic for this forum, but if you're struggling with the unplanned pregnancy, and what to do about it, we have a great forum that you can post your situation to, for some support and guidance. It's called "Women's choice". Here's the link:
We also have a great Relationships forum, if you're struggling with the relationship with your BF, considering this news. It's tough, no doubt.
You have enough on your mind with the HIV testing, but after you resolve that, you may need those forums above.
Very best to you, I hope everything works out okay. Please do let us know how the testing turns out.