Need some help plz...

Ok so when i went to the store a few min ago i was walking around and all of the sudden felt like i had to go pee, then my stomache hurt like im starving.... i got really faint and had dizzy and had to sit down. When i sit i feel fine but when i get up to walk i feel all shakey. I am eatting a snack to see if that helps but idk what happened... i have had it happen before if i dont eat for a long time before i got pregnant but it hasnt happened since i got pregnant. Should i call the dr or just see if eatting helps. My blood pressure is always perfect when i go to the dr i was just there a few days ago. Any advice or anyone know whats up. I am 20w pregnant. Thanks