Bleeding during my pregnancy !!

Hi I'm 23 years old I have to girls and I'm pregnant with baby number there I am worried because last Saturday night I started to feel pain and then bleeding shortly after . Sunday afternoon I wint to the Er they took blood and gave and ultrasound they women that gave me a ultrasound sad there is small bleeding in the placenta I asked if I should be worried  she sad no that is why your bleeding it's fine your baby's doing really good . I left the hospital the thing that I don't get is I'm still bleeding it's like a Period off  and on !!!! I'm 14weeks today I go see my doctor in a couple weeks has any one experience the same thing !!??