Found lumps on testicles but 5 min later they were gone

Hi everyone,

I was just sitting in a warm bath and did a testicle checkup like I do once every couple of weeks.

I was shocked to find a strange shaped lump, hard to the touch on my left testicle. Positioned on the side and more towards the down part of it.

I stood up to check it again and it was still there and impossible to miss. I checked my right testicle and it had a similar kind of lump on a similar location, but not as big and hard as the other one. I was a bit relieved because of the fact that both testicles had something on them.

5 minutes later I wanted to check it again and it seemed they were gone. Both. I did like 10 checkups after that, in the bath, out of bath, while standing, while sitting, but they are gone. Impossible to find again.

I am a bit relieved by this but not 100%. What could it have been? The lumps were the size of a pea and really hard / firm to the touch. Now I have touched every part of the testicles and they seem to have disappeared.

Should I still go to the doc? Did anyone else have a similar kind of experience or know what it might have been?

Thanks!