feeling emotional with this BFN

so i thought id buy a pregnancy test today because for the last week i have been experiencing sore breast nausea back pain and constipation sorry if its tmi so i took the pregnancy test and got my big fat negative and right now im feeling like crap i feel like a failure in some way and its killing me that it is so easy for some people to get pregnant. one of these people being my sister who is 19 was in a relationship with this guy for a month and a half and found out shes been pregnant for 5 weeks pregnant its killing me ahhh. does anyone else feel helpless