I think I have a sinus infection?

My nose is all stuffed up and sometimes it starts to run. I have a cough and mucus comes up. I don't know what color the mucus is because I swallow it. My ears pop a lot, too. My throat feels itchy too. Recently I started taking allergy pills and these symptoms feel MUCH better. Also, my mom looked at my throat and she said it was red and irritated. She said it was caused by drainage. So does it sound like I have a sinus infection? Also, if you think I do, how long does it take for it to go away?