Yes, your over thinking it. Its meant to be something in the sperm that helps bring it along but u will need ALOT of sperm and chances are, it still wont happen. Bub wont come until it deems itself ready to. Sex wont have an impact on it HTH

PS. Get all you can in now because you sex life will be non-existant for a while after bub is born
This is what the OBS told me - you need a tonne of sperm to make any difference, so unless your body is ready it is just for fun. We tried it & it did nothing, I went 9 days overdue :/