Why did my first time having sex hurt me alot?

So now that i remember i allways thought about when i had my first time lossing my virginity to my boyfriend when i was 13 ( i know i was young chill out) i would throw up not only the first time but even after the first time it would be horrible i would get so much pain in my stomach and i couldn't poop & i would get nauseous, i was scared even having sex because of all the pain in my vagina and stomach. why is this possible? Also i never bleed. i know some people don't bleed but instead have pains. i wonder why?