The worst thing was because I did not as Dana suggests "connect" with the professor. Two months before my mother died, she was very sick in the hospital and I was studying for a test and I just couldn't absorb any of the stuff that night for some reason. I went in the next day, took the test and made a solid F, I got a D for the class...the only one I made in college. I never explained my situation to the professor.
I tried to go back to school a month after she died that summer and the same thing started happeing and it was a great class too, Tudor History. I denied I was going to need to drop until past the cut off date. I got up one morning to drive to college and take the test and I just remember anything so I didn't go. The professor called me and said she was worried because it wasn't like me to miss a test and I told her all and she said, you drop out now and don't come back for the second summer term either, she let me withdraw passing and left the slip on her door for me. Communication can go a long way.
I tried later to get permission to retake the one class and get the D off my record but I was by then at another school as I had moved when I married and they said I would have to live with the D