TMI-but I'm in need of help

What is this. I'm on merina, I had a day of light spotting a few weeks ago. And have

been having unprotected sex of about a month. He's never finished inside me. But lately I have been wanting to do a pregnancy test for my own peace of mind.

But this came out when I was in the washroom today. What is it? Am I worrying for no reason?