I think its worth considering couselling for the paranoia, but it'll go away the more you have sex, because you'll realise you arent getting pregnant. And you're gonna feel ill if you're stressed about being pregnant!
can i ask, are your parents uber strict or religious? Because its like your punishing yourself for having a good time, which isnt really fair! youve been as sensible as you can be, so its very unlikely you'll get pregnant, though its worth talking to your doc about switching to the injection if your concerned your pill isnt being absorbed right. And just remember, even if you did get pregnant, only 1 in 10 survive and most of them die before you even know you was pregnant! I got really paranoid the first couple of time i had sex, we dont use a condom (i am on the pill though), which is somehting im trying to get out of the habit of doing, but its just so much more conveinient not to, which is really bad! So if anyone here "deserves" to get knocked up, its me!
So if you put the reliability of your protection to the 1/10 survived pregnancies, im sure you'll be just fine. but its worth maybe talking to a doctor about your paranoia, but you know its irrational. Im the same! but the more ive had sex, the less paranoid ive become. I would however suggest you wait for a more settled relationship in future. Because you dont seem to have too good a view on sex, but its really quite fun, especially when its because of love.
I hope you feel better about everything soon, im fairly certain you arent pregnant.