I'm new here, so I hope that this is posted in the correct forum area.

I'm flying in 2 weeks Yerevan, Armenia - LHR (on B-Med, ~5 hours) and then LHR - LAX (on United). I have a 20 hour layover in London (leaving LHR for that time). And I will be 29 weeks pregnant (trust me, not my choice to fly at this time). My significant other will join me for the LHR - LAX portion of the flight.

I'd like to try to get a free upgrade for myself and my significant other from Economy to something better, at least for the LHR - LAX flight. I figure that for the Yerevan - LHR, I am going to have to rely on my Armenian skills and being sweet to the right people to try to get pushed up, but I'd like some advice for the LHR - LAX portion.

1. Should I ask the Yerevan desk person to give me a boarding pass or not? I am concerned that with a boarding pass, I'll be locked into a seat without my significant other next to me.

2. I am going to check my luggage all the way through to LAX. That shouldn't present any problems, should it?

3. I'll leave Heathrow for the overnight layover, but when we come in the morning to check in for the next flight, what can we do to maximize our upgrade chances?

And some answers: I have a letter from my doctor stating how pregnant I am (and I look pretty pregnant, but not huge). Calling United customer service from Armenia is doable, but not optimal. It is expensive and Internet isn't good enough for Skype here. I will do it if I have to though. I have 28,792 United miles and ~10,000 on US Air. I don't know if these are going to help us though. Significant other has none.

Any ideas? Thanks so much!