I had a bump (i think it was a cyst) behind my ear. in the past i've popped them like a pimple. this time i squeezed it and it felt like it popped. but nothing came out. should i be worried about it popping internally? still have a smaller lump?

If a cyst is infected & filled with pus it has to be drained by a physician or surgeon. If it's not infected but is to be removed it should be excised by a surgeon. I don't think people should pop any pimples,blisters or cysts. Your lesion doesn't appear to be inflamed or infected. If you'd like it removed, consult a surgeon. Otherwise I'd leave it alone unless it enlarges or bothers you.