firstly let's deal with some basic facts here about the runaway aspeccts of your story. If your bf is 17, how is it that he has an apartment? Who signed for him that was an adult? Who is watching over him..and how is it that he hasn't been reported for either trunacy or running away? Aren't you both are on the run or at least not able to be 'legal' as far being seen by the authorities? Neither of you can provide for the baby or even know details about the responsibilities of adulthood, much less parenting.
This isn't your fault and your not a bad person for wanting to try. You are just misguided a bit here. Most of us here all were a bit misguided here at that age. The abuse at your home makes it tougher for you..we understand that.
Please get help professional help and counseling. Think PRIMARILY of the needs of the baby here. What is best for the baby is to NOT attempt to raise it yourself under these circumstances.
Neither you or a 17-yr-old runaway can or should handle this. The welfare of this child is the most important part here. Once this child is born, the legal authorities will intervene anyhow as you are a minor.
After the child is born, then you need the right help to grow into a mature adult. You can't do that with a baby. Neither can your bf.
Truly, we feel for you in this situation. It is unwise to even think about raising this baby without benefit of the help of an adult.
Your best bet