K1applicant

It's not really more complicated. I'm in that situation and you just need to go to the US embassy where you want to register the birth and show the birth certificate with the father's name on it. Although, I live in Canada so the father will actually be present when we register her - I guess it might be a little trickier if he's absent? In that case you might need a notarized letter from the father acknowledging paternity or maybe even a paternity test??
 
But all the embassy in Canada requires is the birth certificate with the father's name on it. 

I am also pregnant and my American fiance and I are going with a K1 visa because the processing time is much faster, so I would recommend that for you as well. 
 
If you are a US citizen at the time of the child's birth then the child can be registered and you can apply for a US passport thus proving his/her citizenship when entering the US and would not need a visa of any kind to enter. If you are not a citizen at the time of your child's birth then this does not apply. That might be a little more difficult and require a separate (K2?) visa so I hope for your family's sake that you will be a USC at baby's birth. I can't help you much more than that because my daughter's father is an American by birth in the US and has been a USC all his life. Don't assume your child will be a USC though even you are naturalized at birth - that's something you really need to look into. I don't know if being naturalized gives you and your family the same rights to citizenship but I don't see why it wouldn't? I know just being a PR/having a green card does not entitle your children to US citizenship though... someone on here should be able to answer that. 
 
It's a matter of personal opinion I guess but I (and majority on here) have not found a lawyer necessary. They just want to pocket your money. None of the paper work is in any legal jargon that only a lawyer would properly understand. It's tedious but very straightforward. Just requires a lot of work. The only time I would suggest a lawyer is if the couple's second language was English and they wanted to make sure the instructions were followed. Even then, everyone on this site really tried to help each other out which makes it a great resource. Just make sure you read and then reread all instructions VERY carefully. 
 
Good luck!

It's a nice train ride from Western Canada.

Remember as well that as a K1 your petitioner will file 2 affidavits of suppprt.  The I-134 is not legally binding and is presented at interview.  The I-864 is legally binding and is sent after marriage when you adjust your status.  

I compiled it exactly as the guide instructed and had no trouble at all.
http://www.visajourney.com/content/k1guide

I agree, it does. The instructions say "complete the information below and clip this form to the first page of your application package". I read somewhere else that they want it first, but I bet you can get away with putting it behind the cover letter too. Like I said, we put it behind the very last page of our package and it went well. But the check is the most important, they want their money, so put that one absolut first.  

Thank you!

Yes, good thinking I am currently going through our texts and screenshotting! Luckily we are big on sending lots of sappy messages lol and it's great because the date is right there. I have a NEXUS safe traveller card (like a super version of the enhanced license - it means they've checked into your background and you're considered a safe traveller with no criminal history) so I don't use a passport to cross. But thanks for confirming the screenshots of messages

Whoa what are you talking about "imagining scenarios"? I'm not imagining anything I have described my exact situation in detail and I'm just asking questions as to how to best go about it. Where did I say I thought they would be "surprised by my getting pregnant"? And for all I know they might go by what the medical community says and consider this is a child.. I just don't know that's why I'm on a forum asking these questions because that's what these forums are for.. to ask questions. No idea what your rant is about but if you're not here to offer some useful advice then keep it moving. 
 
And to answer your question about why I would think to include pictures of sonogram.. uh, why wouldn't I? We have the burden of proof in regards to showing it's a real relationship and that we've met in the last two years. A pregnancy will answer both those questions quite sufficiently, no?