Two days ago I was brushing my dog when I found a bump in his belly right above the penis. It's a soft, 0.5cm × 1cm diamond shaped bump and its color isn't too different from the skin around it. I’m anxious, since Shar is my first dog. It looks a little swollen like an insect bite in humans, though I can't see a scar where he might have been bitten. He doesn't particularly show signs of itchiness. I'm planning on taking him for his first trim tomorrow or the day after, but should I take him to the vet before that?