Hey BB, hope your trip ended well.
Ok, here is my advice on the situation, take it or leave it. I think you have the right attitude about all of this so keep that up, because I think in the long run this (the relationship) doesn't have a chance in hell of lasting but we'll see.
Here's why. Here you have an older, (30 something right?), English white women, who has a very physically demanding, outdoor, very busy career that she loves. Impregnated by a much younger, black, career oriented, NOT EVER gonna get married type of guy.
See the problem here? You two are so far opposite of each other in life you couldn't have picked a worse time to start poppin out kids. This woman is going to have to give a up a career that she loves, for a while at least, to have a kid and start to raise him, all the while knowing you will never want to get married!
I'm just trying to imagine someone I know who could be in a similar situation, like my sister or something, and wow I can't even begin to tell you the family scandal that this type of situation would bring about. Unless she never talks to her family anymore, she is going to be under some tremendous pressure very very soon from them wondering what in the heck she is doing.
She's coming up on middle age, about to have a kid and give up a career for a guy she will never marry and that she really hasn't known for that long....I just don't see how she is going to be "ok" with this when push comes to shove without her knowing that you will get married and she will have the security of that for her and the kid.
I'm not telling you this in hopes that you go out and get an abortion or something, (I mean you had unprotected sex, deal with the consequences), but more as a word of advice that a little further down the road, imo she is going to start getting VERY PUSHY about getting married, and a lot of tension is going to be created over this.
Hopefully you guys can work through it, but it's not going to be pretty that's for sure.