So true Annie - or as my mother in law put it "when the blood fills the penis, it leaves the brain" :)
If your mom does not know you're having sex and you don't want to tell her, I assume you are rather young? If so, I would second the notion that you not "keep trying." You've got time.
I would, however, for general purposes, tell your mom sometime in the next few months that you'd like to get set up with an ob-gyn. You have a woman's body now, you should have a woman's doctor, not a pediatrician. (Points if the ob-gyn is also a woman.) Most women's main doctor is her gynecologist, simply because of the need for breast exams and pap smears. It's not unusual for a teenager to have an ob-gyn.
If your tries to have sex with your boyfriend were unprotected, take a pregnancy test in a couple of weeks. It sounds like the sex was too painful for you to have tons of lubricating juices, but if you did and if he had pre-ejaculatory fluid, there is a (very, very slim) chance of pregnancy if you two went at this unprotected.
Be careful, sweetheart. When a boyfriend gets sex on his mind, he is not thinking of your best interests. As the saying goes, all his brains go to the head of his - - - - . You're the one who needs to say what feels right to you, and to watch out for your health and your future.