Jamie,
I think you SHOULD be asking him to support you. You won't WANT TO or BE ABLE TO go "straight back to work once baby is born" and if you've been living here and not working, you won't qualify for the UK's maternity leave payments (though you may qualify for some other support).
If you are living in CH and got a permit by following him, the fact you've already separated needs to be reported, so you'll need an attorney to find out what you should do (what does your permit say?). If you are living in France, different story, but as you've been together 4 years (get proof together such as old rental contracts with both names), it's civil law so also you'd need an attorney.
If your partner is here as a diplomat this complicates things HUGELY.
Finally, get yourself a GREAT independent midwife and/or OB/GYN who has time for you. And, especially as you may be birthing alone, a doula (disclaimer, I am a doula, but I am not suggesting this to get myself work, I am suggesting it as I am also a single mother).
For a birth in the UK the website is http://doula.org.uk/. If you choose to birth here, English-speaking doulas listed http://www.expatdoula.ch.
To find a midwife in Geneva
http://www.sagesfemmesgeneve.ch/ or www.arcadesagefemmes.ch.
-Michelle
Sep 16, 12 09:17