Pre-seed question!

Lola • Trying for a rainbow baby ♥️

Just tried pre-seed for the first time! Used less than the amount said on the box.

My question is when do you use it? Like you can put it in 15 minutes before but how do you know you're having sex? Not very sexy pre-planning sometimes you have too depending on your circumstances but I would find it really difficult.. plus don't want to stop half way through?

What works for you?