Hi! Many thanks for your question on eHealth forum!
The various causes for vaginal bleeding after sex or after fingering are injury and friction, STDs like Chlamydia, gonorrhea, and trichomoniasis, cervical polyps, yeast infections, non specific vaginitis, endometriosis, cervical dysplasia which is a precancerous condition, uterine polyps, uterine fibroids and cervicitis. None of them are conditions that should be ignored.
Since a confirmed diagnosis cannot be given on net please discuss these possibilities with your gynecologist once and get the required tests like internal examination, PAP smear, vaginal swab test for STD, and ultrasound.