Is it normal to have overflow of cum

Because I take a lot of pills for physical ailments I tend to sit rather than stand to go pee a lot of times because getting a stream started takes a bit and when you gotta go, really bad, standing there for 10-20 minutes gets old and exhausting. Well anyways, I noticed on more than one occasion that there is a white-ish substance there in the toilet. It looks to me like cum but more solid than fluid. I don't have any diseases or nothing like that at all, I have medical marajuana card I hardly use. Anybody has any clue what it is let me know. I think perhaps it's like cum or pre that is a result of blue ball syndrome.