My 20 month old daughter has started showing a rather strange symptom. She is perfectly fine and active during the day, as usually. However, for the past two nights, she will go to bed, and after sleep 3-4 hours, she starts choking, so much that she wakes herself, my husband, and myself. And then the choking/coughing continues violently for 2-3 hours. Then she goes back to sleep. Should I take her to the doctor and risk getting something?