Hi, I am having a similar problem. My period was due April 3rd, I took 3 HPT, one on March 30th (negative) one on April 1st (negative) and one on April 6th (negative.) My husband and I are trying to conceive and had unprotected sex on March 13, 15 and the 20th (around estimated ovulation time.) I'm having light nausea, sore breast and my skin is getting really clear and pretty. The only reason why I am having doubts about the HPT is because of my first pregnancy. With my son, I went to the Dr's office for prenancy symptoms thinking it was a stomach virus or something (at the time, it never crossed my mind I was pregnant.) The test came back negative and I was fine with that. 2 weeks later I went to see my doctor again for something unrelated and SURPRISE! the test came back positive, when they did the ultrasound about 3 days later it showed I was already 7 weeks pregnant. I guess if I was pregnant I would be 4 weeks (this is counting from my last menstrual) I guess my question would be...How likely is it that I could be pregnant but HPT not show until 7 weeks?? Could the same thing be happening as my first pregnancy???