Advice all pregnant women

Im 7 weeks pregnant and had a bit of a scare on saturday with bleeding alot... so doctors are sending me for a scan 2moro just to make sure baby is okay... they said baby is but i think its more to reasure me really.

This is my first so never had a scan before so just wondering do i need to drink before the scan or not as the doctor didnt say and people are saying i do and dont???