pregnant or just hopeful?

So my boyfriend and I haven't been necessarily  trying to conceive but I am not on birth control and we pretty much are doing a "it will happen when it happens" kind of deal (we want kids. we're not stressing it, so to speak, just enjoying each other) . My period has been irregular in the past but since coming off of birth control my period has come on time like clock work given a 1 day difference. My period is now going on 7 days late (from it's due date)....I'm slightly crampy and my boobs are totally swollen....I also had a little bit of brown spotting around the day my period was due but it was gone by the next day. I also, TMI!, have had this clear discharge for days that is super sticky and sometimes there's globs of it! Like it does when you're ovulating...im just wondering if any one else has ever experienced a similar situation? Could I be pregnant even tho the test came back negative? I'm calling my doctor tomorrow to make an annual appointment and for a test.