Orgasm...

Ok so my SO and I are TTC baby #1 and this stuff has been running around my mind for a while now, is it better to orgasm before or after he does? When it comes to me orgasming can I use pre-seed and then orgasm then him? Can I still get my BFP if I orgasm first? I usually ride him but with us TTC it’s been doggy style. I can’t orgasm while doing it doggy style so could I let him get off and finish then use my vibrator to get my orgasm? Also why is the female orgasm so important in pregnancy? What does it help the sperm do? Also if I let him get off and lay with my butt in the air to let gravity help.... will I get a UTI? What are some things u ladies are trying to TTC? I’m not talking about the ovulation tests and the other stuff just the kind of stuff u do at home? I’d like to hear it all! I’m willing to try it all! Thanks in advance!