Bleeding after abdominal ultra sound?

Hi, I'm 13 weeks and just had an abdominal ultrasound.  The ultrasound tech was pushing around on my stomach quite a bit to get the baby to move.  I had light cramping afterwards and then woke up his morning to some bright red blood.  There wasn't much.. It just covered he toilet paper when I wiped.  Do you think they shook something loose during he ultrasound?  Should I be worried?