I think if you had the swine flu jab last year you will still be covered against swine flu this year, and maybe even some other seasonal strains that may have mutated with swine flu. What's being offered this year is seasonal flu with swine flu as a component, as they are worried that swine flu is mutating with seasonal strains. You should be fine! (Though not covered against normal seasonal flus unless they're also a bit swine-y, IYSWIM.)
As far as I know, during breastfeeding is fine too.
Does anyone know what the current NHS/DoH guidelines are for flu vaccines and the under 5s? I am getting confused -- on the NHS Direct site it looks like the under 5s (and over 6 months) are a "high risk" group for swine flu who should be vaccinated as a matter of course, but GPs surgery are saying they are not giving flu vaccines to kids. I know that the swine flu vaccine is now wrapped into the seasonal flu vaccine and that there is no official pandemic, but the guidance on the under 5s still seems to be out there.
I asked the nurse this afternoon after my jab, and she said they withdrew the invitation to under-5s after making it last flu season. I said 'was it just a matter of cost?' and she said 'well, it was seen that under-5s were coping well with swine flu... actually yes, it was a matter of cost!'
As far as I know, under-5s are no longer considered high-risk unless they have an underlying condition. They were, last winter.