Need advice!!™

Glenna • Proud momma of an angel baby 12-07-06 and two handsome boys 10-11-07, 07-25-10
My hubby and I just had sex, I was on top, he pulled out and finished when I got off of him we both noticed some discharge that was tinted brown. It wasnt his cum and AF ended last week, what could this be? Its never happened before. Please help me!!!