What Causes Bleeding During Digital Stimulation Of The Vagina?

Hi, I am 18 years old (around 160cm tall and weigh 47kg) and have started sexual activity a couple of months earlier. I am still a virgin but have tried oral and have been fingered many times by only my boyfriend. My query is that nearly everytime he fingers me, I bleed. Is this normal and am I at any risk of getting pregnant if I continue with what I'm doing? Thank you for your time.