Im 10 weeks pregnant, this is second time i have fallen down, suddenly i fall down and i feel like for few seconds my heart skips beat.

Falling Down: While it may be very minor, or nothing wrong at all, when i hear someone is "falling down" and feels as though their heart "skips a beat, " I have to wonder if there is an irregular heartbeat causing it. I would see your physician and let him or her know. They may want to order a heart monitor that you "wear" for a while to make sure your heartbeat (among other things) is ok.