Hello, I'm Kayla. I'm 18 and 4 weeks ago, I had unprotected sex with my fiancˇ. I decided to get a blood pregnancy test done 2 weeks later. Negative. I am now 10 days late for my period. My periods have never been late and I have not been under any stress either. I feel like I'm cramping and have been for about 2 weeks. But nothing. Is there a chance the blood test was wrong and that I'm pregnant? I heard blood tests are very accurate so I didn't know if I should test again. Thanks :)