I dropped my iPhone 4S in water but?

It still works; it was submerged for about 3 seconds (if that) and as soon as I got it out I dried it off with a towel. I didn't know to turn it off but I wasn't using it until I got home, and it worked fine. I decided to test it out and I turned it off and on, but the normal loading screen didn't show up, it just looked glitchy. I took this as a bad sign but when I actually got to using it (it did take just a little bit longer to start up) it works perfectly.

Aside from the power off/on thing, it seems to be working fine, I backed up all my information onto my laptop just in case, too. The water damage indicator in the headset jack and the power cord jack isn't red from what I can tell, everything is still white… I had the phone in a wallet style case, so I'm sure that helped, but still. I removed the sim card and it was dry but I dried it again with a cloth anyways, but I can't open the entire iPhone to check the battery right now.

I've heard of people dropping their iPhones in water and they working afterwards but succumbing to water corrosion later on; I don't want this to happen, and I'm wondering what I can do to prevent it, or possibly if there's some way for me to determine whether I'm even at risk of this happening? I've heard of the rice/saline packet tricks, but I don't have either at the moment and I don't know when I can get them next.

What do you suggest I do? Am I worrying over nothing? I know Apple warranty doesn't cover water damage, so, worst case scenario, what happens if my phone DOES become unusable? Will I have to pay full price for another one, or can I just send it in to repair the corroded parts?

Sorry I'm asking so many questions, I just really want to know what my options are here because I'm kind of occupied at the moment (as far as dealing with this situation goes). I really appreciate any insight into my situation, thank you!

Added (1). Again, I don't have rice at the moment and I'm not sure how to check if it's dry on the inside; I know you have to take it apart but I can't do that right now

I'd suggest putting it overnight in a bowl of rice, as it lures Asians to fix it.

But seriously now: P
Put it in a bowl of rice: it will absorb the water mostly.

You can put it in the oven for a few seconds too though, just be careful.

Hi
dissasamble you iphone and clean it with pure alcohool (clean it very good) every part leave it to dry for an hour and assamble!

here a video

or you can watch this


or this

Male sire your iPhone is dry inside and out.

If you ever have to do something with the warrenty, don't ever mention you lost it in water. They can blame it on the water, and won't have to pay.