Dp thinks marriage doesn't mean anythi g and he would feel suffocated to be trapped legally as he hates the idea of not being independent and being bound.
That, tbh, would have my spidey senses tingling. There are absolutely people who don't want to marry for whatever reason, but who are still extremely committed to their partner. And those relationships can be really solid. He, however, doesn't sound like he's one of these people. It would worry me if my partner set such store on not feeling committed to me. Especially if I were planning to have a child with them!
I do also think you could do with thinking about your feelings on marriage as a way of ensuring lifetime security. Much as I sympathise with you, it's not. People get divorced all the time. Married couples are less likely to split up than unmarried (with some caveats) so I guess if you're looking for the statistically more secure option it's marriage, but a very significant minority of marriages end in divorce. Marrying won't insulate you from the possibility of being left again. So even if he does agree to get married, you will have to work through his feelings of not wanting to feel tied down together.
Anyway with all this in mind, I'm not saying don't have a baby, but approach with caution and ensure you're not in a position where you have to rely on someone who's made zero legal commitment to you. Because he hasn't.
You say you're going back for 4 days- ok. What about him? Will this leave you worse off? Is that going to be reflected in your contribution to bills? What about savings? You're renting- so is the plan to purchase eventually? You will need to think about who'll have what shares, in whose name the deposit savings will be until then.