Brief Answer:
No, doing that is not dangerous, but need to understand the cause of it.

Detailed Answer:
Hello,

Thank you for using Healthcaremagic to post your health query.
I read carefully your question and I understand your concern.

It is not dangerous to press at your bladder in order to start urination, but it is important to understand why urination is not happening itself when it should.
Normally there is a muscle which will trigger urination once a person contracts it voluntarily in order to be able to urinate.
If a person has difficulty doing that, then maybe that muscles has some problems.
On the other side, if a person is able to control that muscle but not to urinate smoothly because something is blocking the urine to come out, then again it may be a problem who will need investigation.

So, my advise is that you should consider seeing a local urologist who can examine you, can do a urine analyse, an abdominal ultrasound and other necessary tests to discover the cause of your problem.

Hope this is helpful.
Let me know if you need more clarifications.

Regards,
Dr. Papaqako

---