Bleeding in pregnancy??

Just wondering if its normal to bleed when pregnant? Im 24 weeks tomorrow and last night I started having little tiny blood clots and bleeding a little, not alot but I have to wear a liner. 
Went to the hospital but they said my pains and discomfort was normal and they couldnt locate where the bleeding was coming from at that time so I got sent home. 
The bleeding is kind of like stringy with little blood clots, red and sometimes looks like its mixed with discharge. And I have some abdominal pain but ive always had the pain.
Can still feel bubs moving but it still scares me!