Brief answer....yes,you definitely need to see your doctor
Detailed answer....
Hello,
Thanks for the query.
I have read your query and understand your concern.
Brown coloured semen means presence of blood in your semen.
Very frankly speaking there can be various reasons for the presence of blood in semen ranging from innocuous reasons like enlarged prostate,prostate inflammation,inflammation of seminal vesicles or may be bursting of some weak vessels at the time of ejaculation to serious reasons like cancer of prostate or bladder or testis etc.
You should consult your doctor and get examined and investigated in detail to find the exact cause. Treatment would depend upon the cause found.
I hope it helps,however you are most welcome to revert to me for any further query.
Best of luck
Thanks

---