I couldn't read and run. I'm so sorry to hear that things are so tricky.
Don't make any quick decisions, you've got some time to think and work out what is best for you, and that really is what's most important right now. Do you have family you can talk to, or a teacher, or a good reliable friend?
You're probably worried that this will get back to your parents, and to be honest it most likely will - I know it's terrifying, but I think that usually once a parent has got over the shock of their little girl being pregnant, you often find that they are more supportive than you'd anticipated. I often see parents on forums such as this who have pregnant teenage children, and mostly they're asking how they can support them.
I don't know the ins and outs with the boyf, but he doesn't sound great - so don't count on his support, it doesn't sound like he's able to give it.
There are lots of people here who have had children and had terminations at all different ages - no one will be judging YOU (they might ask about why you weren't using contraception, but I guess that's a natural question, I think in our heart of hearts most of us have had unprotected sex at some point and have only not got pregnant by pure luck).
The most important thing, is to get whatever support you can - so have a careful think about who can give you support you need right now. If no one comes to mind, then book a doctors appt - other posters on might have good ideas for resources/helplines that will be able to help you out.
You're not alone! It's natural and normal to be scared at this point*
*I'm 36, married, good job, nice home and I was still terrified when I found out I was pregnant, pregnancy is scary!