36 years female. sensation of tiny air bubble escaping after standing up after urination. no other symptoms. what could be wrong?

See below: Most likely cause is trapped air in the vagina which escapes out with a change in position and is usually of no clinical significance. This may occur because of altered anatomy in the genital/pelvic region that can occur with aging, childbirth, weight gain, pelvic floor prolapse or weakness, etc. For reassurance, helpful to have pelvic exam and U/A to assess above and to rule out UTI, fistula, etc