Pregnant Sex?

I am newly pregnant, 4 weeks and 3 days. I’m slightly nervous about having sex now that I finally conceived. My husband and I have been trying for a while, and I know it’s ok to have sex while pregnant, it just makes me nervous (sorry if TMI, but he’s pretty well endowed haha and I don’t want it to affect anything). Any suggestion on what to avoid or safest positions? Thank you!! :)