another thing i forgot to add, the decision to use hormonal bc is between you and your dr. it is not up to your bf. you can take his feelings into consideration. but ultimately, you need to make the decision for you. you cannot base it on his ignorant assumptions.
You both need to have someone who knows about these things talk to you both. Its clear neither of you were awake in health class if you were in the USA.....not sure if they teach these basic things in schools outside the USA if thats where you are.
Because based on what was said about you both its clear neither of you understand contraception or human reproduction. Its not intended as a smart remark, its intended to get you to learn more before you find yourself expectant parents without a clue how that happened and why.
If you knew your own anatomy you would understand why your assumption in the original question is so wrong.
Take a mirror and look at yourself down there you will see a small opening above the vagina where you pee. The vaginal opening below that is where you have intercourse...its clear why urinating after, before or during sex can't possibly have any effect with any sperm left behind because they aren't in the same hole....and has been said a great number of times...sperm are microscopic...it only takes a single one to get you pregnant and there are hundreds of millions in the average guys ejaculate. And the buggers are even coming out before he ejaculates. Which is why with drawl is stupid to use as birth control.
Crossing your fingers and praying is NOT an effective contraception method.