Period late

Okay, I just need some feedback. My last period was sometime in the first two weeks of September. But before the 15th. I had sex several times after the 16th and the last time I remember was septwmber 21st. I have not yet had a period in October, but I have some spotting & used a liner twice but was mostly brownish & not much. I'm usually regular. Some days I have a bit of cramps & when I go pee I'll wipe & lite red and ither days nothing. Should I worry? I have not taken pregnancy test and I'm waiting to see my Obgyn this Thursday for my annual.