Not sure if it has anything to do with your pregnancy, but i had the same problem at age 15 when i had a bleeding stomach ulcer. 1-3 minutes after i ate something i got really shakey and weak. Sometimes i felt like i had to pass out.
Not saying that this is whats wrong with you, because im not a doctor. But you might want to ask your doc about it. Could be just an upset stomach, which is normal when pregnant. But only the doc can tell you.
at 12:34 PM on Feb. 1, 2009