This is one of the more Frequently Asked Questions on "help" sites.
What it shows
is that you have not had the opportunity to examine other men's (or boys') penes and scrota (plural of scrotum). Which is perhaps not surprising, but a little sad. There is by and large, no harm in doing so, there is nothing wrong with curiosity.
harmful is the suggestion that doing so - simply examining each others' genitals for reassurance - indicates a "homosexual tendency" because introducing such a notion into young people's minds can cause them to presume
that they are in fact, "homosexual" and proceed to base their subsequent relationships on that expectation where in fact, they are simply too young and inexperienced
(of life and relationships in general, not just sexually) to understand their feelings.
Which is to say, if you had
investigated other boys' genitals, you would already know
that what you describe was perfectly normal and common, if not universal. Just for an example, take a look at this site
(not that there is of course any shortage of such examples on the Internet in any case).
The other aspect of this is - why is it that you seek to pick fault
with your body? What is the more general problem that you are sitting there wanting to "fix" something - why do you feel this way? Of course, we are absolutely pleased to offer you help for any
aspect of your genital health and sexual activity, but does the fact that you have found yourself here indicate some other concern? If so, by all means tell us.