Not sure what to do

I'm looking for some advice, so I'm turning to you guys for some thoughts on this situation.

My pregnancy is still a secret, so I can't turn to my boyfriend's family or even mine for answers.

My boyfriend and I have been together 7 months. We're pretty serious. He has a 5 year old son. His baby Momma is a total C U Next Tuesday.

She makes their son carry a tracking device watch in his pocket or on his wrist. My boyfriend's sister can have him for 24 hours and baby momma won't call or text. The moment he gets him, she calls 4 times and texts him all day. She asks for updates every time something changes. I get that if my boyfriend had been irresponsible, but he's been a great Dad. He only gets his child 1 day a week for maybe 8 hours. If he's lucky, he can stay the night. He's basically not allowed to have any contact with him until his day to get him. She's very controlling. And unfortunately, my boyfriend doesn't have the money right now to go to court over this.

So I am almost 6 weeks pregnant. I feel like once she finds out I'm pregnant, she's going to take his son away for good. She always controls him with his child. Now my boyfriend is reluctant to have a child because of her. I feel like now I can't have my own child. I feel like even if I have this child and give it up for adoption, it's still going to be an issue with her. I feel like my only option now is an abortion. That's the last thing I want. I want this baby really bad, but I'll feel so horrible if his son gets taken away because we are having a child.

I really want to talk to him about this, but this whole pregnancy and his son is a very touchy subject with him.

Any advice?