Can anyone help me? :(?

for the past month I've been feeling really off, my emotions are a roller coaster, one minute I'm happy and the next I'm angry and one second later I'm crying! On top of that I'm always tired and I'm always thirsty! Even my dad has noticed I'm way more irritable lately! even my cat meowing is making me irritated.. I'm also scared because i didn't get my expected period last weekend, and I've been on my birth control for the past 3 years so i always get it the same day. I also got my wisdom teeth out last friday so I'm not too sure if the antibiotics had something to do with my missed period, but I'm nervous and i don't know what to do or think :( someone please help??