Fiance Visa and the NHS

I'm sure this has been asked a million times but as I get closer to starting my visa process I'm getting a bit worried.... and stressed 

I have no idea how to apply for a NHS number. Do I get one once I move, do they assign one, do I apply for it?

Thanks for your help in advance

After I registered with my GP, I got a letter in the mail from the NHS with my number on it.

They assign you one. I didn't actually get a copy of mine until I had been here for three years. No biggie.

Honestly, the NHS number itself isn't all that important - you are assigned one automatically when you register with a GP, but you will probably never need to actually use it... it's more to keep track of your records on the NHS computer system than anything else.

I was apparently assigned an NHS number the day I was born, but I didn't even know there was such a thing until I was 24 and I found this forum - no one had ever told me what an NHS number was or that I had one, and I've never needed to use it.

When I changed GP surgeries recently, I called my old surgery to ask for my NHS number and they told me I didn't need it and wouldn't even tell me what it was... they just said that as long as I give the new surgery my name, date of birth and the address of the old surgery, they could just look it up . Sure enough, when I got my next prescription at the new surgery, my NHS number was printed on the top.

Thank you everyone for your replies. I feel so much better knowing this information.