I had a fall at 40wks and when I rang the midwivEs they told me because I fell I should come in and get checked out. When I got there, they kept me for 4hrs to watch for signs of distress, bleeding, waters breaking or labour starting. I was on the baby heart monitor the whole time. My fall sounds similar to yours.

Call the midwives and see what they say. I might differ coz your carrying twins. Best of luck xx