Alright, I have been playing clarinet for 5 years and this has never happened before. I can't reach my lower register, like whenever I try to play low G, F, and E it goes up to the higher register, and I'm not putting the register key down! What's wrong with my clarinet? It's not a reed problem either, I've tryed it on 10 different reeds, and 3 different level of reeds, 3 1/2, 3, and 2! All of them don't work! Can someone help? Do I need to bring my clarinet in to get fixed?

something's leaking, most likely

leak!

Take off the top joint and the bottom joint. Cover ALL holes, plug the bottom with your hand and blow in to the top. If you hear something leaking thats the problem.. You should get it repaired. It's happened to my G# key a few times. Also remeber to do the same thing to the bottem.

It might be your embouchure.if it does that then you just have to drop your jaw.

your probably putting to much pressure on the reed. loosen up a little. if not that then send it in for a checkup. a repair man will find the problem