My husband and I have been having sex throughout the pregnancy so far. But usually I'm on top. He is 6'5" and 300 pounds and I'm 5'4" and 180. Last night he got excited and he got on top. I kept asking about the baby and he said it was fine. But I'm scared. He is so much heavier than me I'm worried about the baby. What I've read online says missionary is okay in the first trimester if comfortable. Just wanted to see if any one had the same concerns? I'm 12 weeks today.