Hello, I Am Experiencing Unexpected Vaginal Bleeding, And I Am

Hello, I am experiencing unexpected vaginal bleeding, and I am really not sure what is the cause. No pain, and no other symptoms. Just random bleeding. My partner and I have been having intercourse for a while and all of sudden this happens and would really like to know if I should be concerned. This has never happened before and he is my first and only sexual partner. Hope to hear from you soon! Thanks!