I am 15 years old. First I will let you know about my body. OK, so I am short -- 4'11 and weigh only 78 pounds. I started puberty, i think, a year or two ago. I have a good amount of pubic hair around the penis and groin, although some are very long but some are getting a little curly. I have black short hair around my anus, and some thin black hair on my armpits. I have no hair on my chest and peach fuzz below my nose. Also sometimes my nipples swell up but normally one at a time. One strange thing is I ejaculated semen before but never had precum, so I don't know if that's normal. Also my penis is about 4 1/2 inches maybe 5 inches erect. I have not measured my balls, so I dont know about that. OK, so now you have a gist of what stage I am at.
So here is my question: As you can read in my description I am a late bloomer, and I have to go to the andrologist, and I want to know what I do their for the exam. Do then make me ejaculate sperm, check my prostate, touch my penis and balls, and look in my penis hole? I don't know, and I am curious about what will happen, so if you could give me some information on it, like the process, that would be great. Thank you.
Yes, you are a bit late in developing, but not outside the range of normal. I would guess that you are somewhere near the start of stage 3 in development from your description. Having precum doesn't develop at the same time as being able to ejaculate, so that you are able to do one without the other is not unusual at your stage of development.
What I'm trying to figure out is why you are seeing an andrologist (a specialist in fertility). Boys with suspected developmental delays more typically see an endocrinologist (a specialist in hormones). If you can tell me what you are being seen for, I will be able to tell you what types of tests the doctor is likely to do to solve your problem.