Question about conceiving

So my last period was July 12-16. Since it ended I have had white cm only which is not normal for me. My next period is due in a week. My fiancé and I had unprotected sex last night and he thinks he might have finished in me a little. Which is fine, we have our own place, both of us are done with college and a baby would be a welcome surprise! My question is, does it matter how far away from my period I am to be pregnant? Like since my period is only a week away is there a chance I could get pregnant anyway since it's outside my fertile window?