Missed Period & Negative Pregnancy Test: What to Do?

Question
We have been trying to get pregnant. I am 24 years old. I am on a 28 day cycle. I was supposed to get my period on the 20th. I didn t recieve it, So I took a pregnancy test. It came back Negative. It was First Response.  I have never taken any kind of BC. My period has been exactly the same since I was 16 years old I even know an hour time frame in which it comes. I have only missed my period once, 11 months ago. My ex and I had broken up after 7 years together. So i went to see my doctor. She ran a bunch of tests including stds, ultrasounds, Ct Scans, Mri, Urine tests, ALso a full blood work up.  Everything came back perfectly normal. So my doctor said it was due to stress.  That was kind of a give in! Hey better safe then sorry. I havnt had any stress since. In fact my life is wonderful. The thing is I took the test it came back negative. I was wondering if it could be wrong. I thought I was going to get my period I had all my regular signs of it. My breast are slightly tender. I also have Slight cramping but not like I normally get them when I get my period..they seem a lot lighter. I did notice I have been urinating more frequently in the past week. In fact like 4 times more. Almost once and hour. ALso have been nauseas for like 3 weeks now. Have also been having hot and cold spells. But no temperature.  Sorry about the long story. Anyways I was wondering if the test could be wrong? If it could be something else. It s only been 11 months since all the testing.  So I dont know what else it could be.  Thanks for your help.

Answer
When was the first day of your last menstrual period. If you have a 28 day cycle, and you claim that you were due for your period on May 20, then your last period probably started on April 23. If so, you probably ovulated on May 6 and could have conceived only if you had sex on May 5,6,7, or 8. The best time to take a pregnancy test is seven days after missing your period. You were due for your period on May 20. Therefore, the best time to take a pregnancy teest is seven days after missing your peeriod. If you do not get your period by May 27, take a pregnancy test.