Hi, my wife had 32 to 35 days cycle and we had intercourse from her cycle day 12 to cycle day 20.. Her last period was dec 27 and expected period was Jan 30.. Now her periods are delayed by 16 days and we have been testing using pregnancy kit from last one week and getting negative tests. Is there any cases where test was negative but the woman was pregnant? Do we need to any extra checks for her.. She is healthy 25 year old with no over weight or anything. What is the next step for us now? What are the chances that my wife is pregnant??