Do you need his money to be OK financially @solosunflower? From what you said earlier, it would make a big difference.
As PP have said, he can ignore your baby if he chooses but that doesn't mean he doesn't have to contribute financially. He doesn't have to see his baby, but he does have to pay.
I commented earlier in the thread. I split up with my ex when I was pregnant. He ignored my texts and so did his friends. He has never seen his babies (twins). And honestly, the freedom has been amazing. I read some awful stories of trying to co parent on here and I'm so weirdly grateful that I didn't have to worry about any of that. My DC are 13 years old now and they're happy, fulfilled children - they haven't missed having him in their lives. It's entirely his loss.
However, I didn't ask him for CM. He was self-employed and working at his dad's company - I know they would fiddle costs to make sure he barely had to pay anything. I decided I didn't want him to ever try and play the victim - forced to pay but denied access. He has a previous child by another woman, and that was the story he told me. (I fell pregnant due to contraception failure - I hadn't planned to have children with him). I've never taken a penny from him and that suited me. It's been tough at times but I managed - given his attitude and complete refusal to acknowledge the birth, I didn't want him to be involved in any way.
I know most people will say I should have claimed CM but I didn't want him to be part of our lives in any way, or to stake a claim. I'm not saying what I did is right for everyone, but it was right for us. And remember, you can change your mind. If you don't go for CM now, it's not a forever decision - you can still lodge a claim at a later date if you need more time to decide.
The one thing I would say is that if I'd needed CM to look after my children properly, or that it would have made a difference to my career choices to work around my children, I'd have put the claim in. Try to remove yourself and your emotions from the decision and work out what you need to carve out the best life for you and your son.