HELP! ABS & BRAKE LIGHT ON SIMULTANEOUSLY!

[mizhgolightly]

I have a 2007 Yaris which I just bought less than two years ago and yesterday when I started the car the brake light & ABS brake light went on simultaneously. The speedometer is working fine. There was an incident 2 days ago when I was driving and an ambulance ran a red light but didn't turn its siren on so I had to brake very hard and abruptly which made the brakes screech a bit.....also, there is alot of snow here right now so I'm not sure if that affects anything? I have winter tires....but I was just wondering a couple of things:

-what could possibly be the problem?
-will it be expensive to fix? If so, approximately how much?
-I have the toyota extra care protection - will this cover it?
-is it still safe to drive around the city in it? I have an appointment at my Toyota dealer in three days but I need to run some errands with my car before then....

PS. I don't know ANYTHING about cars....