If you've gotten swine flu once, can you get it again?

Unlikely.: The strain really has not changed enough to evade immune response from people who have had it.

Yes, but:: Swine flu is a broad term, can mean influenza from several strains viruses that also affect pigs. You'll be immune to the strain you recovered from, but can get other strains. Sometimes you won't get as sick the next times, because you have partial immunity from the previous attack. Vaccines are created every year for the strains predicted. See https://en.wikipedia.org/wiki/Swine_influenza