Welcome to health care magic
I can understand your situation. I appreciate your effort to seek online support.
Since you have increased frequency of urination after sexual intercourse and that too without contraceptive
measures, it might be you have some Urinary Tract Infection
(UTI) which is quite common in such cases. I advise you to get your urine culture done.
Secondly, use of a contraceptive is strongly recommended as it prevents against such infections and other sexually transmitted infections.
However, consult a gynaecologist for detailed work up and rule out any other possibility.
Hope it helps
Dr. Gourav Monga