Would really like to know whats going on?

So I started my last period on October 30th and ended Nov 5th. My husband and I are trying to conceive but instead of keeping track of ovulation we just BD every other day. We have also been using preseed. For the last couple of days I have had tender and abdominal cramps. Yesterday I started spotting at first it was brown then turned like bright red. I have pretty regular periods and wouldnt expect AF for another couple of weeks. Any ideas what could be happening?