White "floaters" in semen and hurts to ejaculate

Hello. I am 17 and I masturbate every day about twice a day sometimes just once a day at night and some days I completely skip. I noticed that at least about once a month, maybe 2 at the most, when I ejaculate, it burns a little but not too bad. This has happened many times throughout a year or so but never raised concern until I recently got curious of what it might be. One time when it hurt to ejaculate, I put my semen on my bathroom counter and looked closely at it and noticed there were little white floater looking specks in my semen. I always look at my semen after masturbations and noticed its only when my ejaculations hurt, that I find these white specks but no other time. Does anyone know what this might be? Thank you.

[al259]

Oh and also, I have had sex  with 2 people in my life 1 time was with a condom and then the other person was without one but she doesn't have any stds