There is no seminal fluid in the spermatic cord or vas deferens. Only sperm are there, carried in a little bit of a watery/mucus type fluid. So there's nothing to get blocked up there. Seminal fluid is all produced by various glands inside the body near the penis, including the prostate and seminal vesicles.
You may have a bit of blood congestion or swelling in the veins surrounding the spermatic cord and/or testicle, often caused by prolonged states of arousal. Sometimes referred to as "blue balls". This is usually only temporary and will go away by itself.
Does anything feel swollen or out of the ordinary there?