I can't imagine the pain the loneliness you must now be going through. I wish you all the best in the future.
Obviously no one can make this important personal decision but you, and please don't feel you need to decide based only on someone else's opinion.
My opinion, for what it's worth, is that the pain of your boyfriend's death, followed by the discovery of the pregnancy mean you are currently in a very emotionally vulnerable state, and that's not the time to be making important decisions. You won't feel like you do now later on. Now you can gather information, compare the pros and cons, and if you are a woman of faith, pray about issues. Think long term. How will you feel 5 or 10 years from now? If you are comfortable with that answer, you know what you need to do.