Anyone else have this? TMI kind of..

Andrea • TTC baby #2 I would love to give my daughter a little brother or sister.
AF is due Friday. My SO and I just BD afterwards I had some light spotting. And when he wiped off it was like a light brownish pink. Anyone experience and they turned out being pregnant? I periods are barely ever early. But do u think AF is coming early or has something to do with pregnancy?