My sperm is brown what should i do?

[Jayjay769j]

I had surgery on my bladder when i was shot. They put a catheter in and i had it for about 4 weeks. The catheter caused my pee to turn a dark brown. I went back to the hospital and they took xrays to see if my blatter healed back and checked for leaks. They removed my catheter and said that the catheter some times can cause irritation to the urinary track and can cause an infection. They gave me antibiotics and said to take them for a week and it should take care of it. In about 4 days my pee returned to the normal color. I masterbated after i thought it was okay but my sperm was the same dark brown color that my pee was even though my pee returned to normal color. I only have 2 more days of antibiotics and im worryied that it wont fix my sperm. I dont know why my sperm is still the same color as when i got the antibiotics.  A dark brown and i dont know why. It freaks me out. I need some advice on what to do.