Pregnancy test.. Help?

Needless to say I have been having a strong gut feeling that I am pregnant. I had a very weird period last month (May) and now have some pregnancy symptoms.. I took a pregnancy test around the 24 of June (at night) &had a very light positve line. So I thought I would wait to take another one with a different brand AND use first morning pee, I took the test yesterday morning &it came back negative. All tests were read within the time limit, has this happened to anybody else? Im just lookin for some thing to explain all this, im so confused &me and my husband were highly disappointed with the negative test.. Help? Oh &i have not yet recived my period for june, don't know when to expect as they are irregular..