Last Friday I began experiencing sore breasts, back pain, stomach feeling yucky and briefly feeling lightheaded. It lessened by Sunday or Monday and was minimal by Tues. I tested but came up with BFN. My period started Tuesday evening which was 3 or 4 days early. I don't normally have PMS symptoms and have never had anything close to this. I'm trying to determine if this could have been a pregnancy. Anybody have any thoughts either way?