Hi there.
First, short anatomy lesson:
1. Cowper's gland secretion ("pre-come") occurs during sexual arousal. If you're aroused frequently, then you'll produce frequent Cowper's gland secretion. It has no effect on orgasm
2. In men, orgasm and ejaculation are two separate actions--most of which occur together. Whether semen is produced earlier in the day is irrelevant, since your body continues to produce semen as needed. There is no "reservoir."
However, frequent arousal MAY (but not for everyone) reduce sexual tension, leaving you without enough tension for orgasm later.
In order to determine whether this is true for you, why not reduce your arousal during the day for several days in order to build up sexual tension? Try this and see if it works.
Also, try having an orgasm first thing in the morning to see if there's any difference in the quality of the experience and the tension build-up.
After trying this, if you're still having orgasm difficulty, I'd advise you to see a urologist to see if you have any contributing physiological issues. best of luck to you. Dr. J
I usually knock one out if it's gona take all day. I've ran into this issue as well. It seems to help me , so you can try it.