Had Unprotected Sex While Missed Pills, Breast Muscles Sore And Tender, Tiredness. What Could It Be ?

okay, my daughter missed 3 pills in her last month pill pack. so, she just stopped and waited for her period to start. she did have a menstrual cycle, restarted a pill pack. she did have unprotected sex during a two week period. so she is now on her next pack for a couple of weeks. has gained 10lbs, is nauseated and does have emesis when she took one drink of an alcoholic beverage. which in the past has never bothered her. breast feel like "sore muscles" some tenderness also. she is extremely tired. I was wondering if the birth control pills are masking the hormone to detect pregnancy and that is why she has had so many negative results. she has never been over 115 lbs since high school. Also, would a lab draw prove to be more accurated than the urince specimen. thank you.