Is it all on the same ticket or are there two tickets?

New rules: "Effective for travel on or after January 15, 2013, Delta Air Lines policy will be to check a passenger's baggage between the origin and destination points that are issued on a single ticket or conjuncted ticket exclusively. If a second ticket is presented for travel on another airline beyond the destination of the first ticket, the passenger will be advised that Delta will only check the bag to the destination on the Delta ticket(s). The passenger must collect the baggage at baggage claim for their Delta ticketed destination, and then re-check their baggage with the down-line carrier for the next flight(s)."

hmm.. im flying in two days and also i bought them separately.

NFZ's post supplies the bad news for you. But I wonder: Why this combo? Delta and its partner Korean could have put this route together for you, all non-stop flights, with no worries about bags and the airlines jointly taking responsibility for delays etc. Just asking; no criticism......

I know..but this was the cheapest option at the moment. However NFZ's post says effective after Jan 2013 so I'm guessing it doesn't apply to me and I don't have to pay..?

Bad news: Effective for travel on or after January 15, 2013, Delta Air Lines policy will be to check a passenger's baggage between the origin and destination points that are issued on a single ticket or conjuncted ticket exclusively.

Less bad news: ...im flying in two days and also i bought them separately.

So when you check in at JFK show both tickets to the Delta person and plead with them to through-check the bag. You might even acknowledge that you know about the change in January but you're really in a jam today, blah blah. They can "interline" your bags, and with just two hours at SFO you really, really need them to do so. Otherwise you're in a real pickle and stand a good chance of missing the Seoul flight; Singapore Airlines would be under no obligation whatsoever to get you to Seoul. Doing a bag claim/recheck itinerary at SFO in the middle of the Christmas season is, no offense intended, mad. Remember you have to check in way in advance on international departures, the counter people have to look at your passport and visa information, etc. It's time consuming, time you won't have.

Frankly, in your shoes, I'd suck it up today, pay the change fee and move to an earlier Delta flight to SFO so you can reduce the chances of a weather or air traffic delay wiping out a Singapore ticket that would cost hundreds of dollars to replace.

thank you for our response everyone.
unfortunately the delta flight was the earliest I can find that day. I guess I just have to take the chance

But do you guys know if i have to go through security again? or can i walk over to the international terminal?