Possible miscarriage?

So my period is 17 days late. I tested on Wednesday June 23rd and got a faint positive line. I tested again on Thursday morning and again faint lines but still positive. I’ve been having constant cramps but nothing unbearable but definitely uncomfortable. I tested again this morning and the test was completely negative. I have not had any type of bleeding. According to my last period I would be roughly 7 weeks. I’m so confused was I actually pregnant? Am I going to have a miscarriage? I will be calling my doctor first thing Monday morning. But looking for advice in the meantime.