I sometimes have vaginal flatulence,i'm a virgin.can that happen if my hymen is still intact?i don't use tampons nor do i exercise,but s/t masterbate

Don't worry: Be reassured this is normal. The hymen only partially blocks the vagina. It's still possible depending how your body is positioned for air to enter the vagina and then be expelled creating the sound you hear.

Even if a virgin: it would be rare for the hymen to be fully intact at your age. If your hymen were imperforate - menses would not flow out of your body.