Brief Answer:
Not necessarily an issue, but can go ahead with a semen test

Detailed Answer:
Hello sir and welcome.

Thank your writing to us.

I have gone through your query with diligence and would like you to know that I am here to help. I would like to state a few facts for your better understanding sir:

+A small amount of semen does not necessarily mean the amount of sperm is lesser than normal
+If you ejaculate very often (more than once a day), or more frequently (e.g. once every day); the semen quantity can be lower than normal, and this is not considered to be a bad thing

But if at all you seem to be observing something that is different from normal and are not used to this, then you can report to a doctor for a semen test and we can accordingly guide you further sir.

I hope you find my response helpful. Please do not hesitate to write back to me for any further clarifications, I would be more than happy to help.

Best wishes.

---