You said "I feel like that’s perhaps not a very mature choice but I don’t want to add the anxiety of knowing there’s a test coming in the mail and having people query me what it is." For what it is worth, this decision feels mature to me! I see you thinking through the different factors, weighing what you are and are not comfortable with, and coming up with a decision that is best for you. Given what you said about your sister being verbally abusive*, it sounds like a self-protective choice to try to not have her involved in this experience. Speaking of, are you wanting a space to talk more about your relationship with your sister and/or receive support? If so, Scarleteen can be that space, if you would like
In terms of sharing with your boyfriend, your concern that it would become more about his anxiety than your own is a very real one. What would it be like to share with him about the pregnancy risk and
state what you're needing -- for ex. that given that this is going on with *your* body and some big feelings are coming up for you, you don't have the capacity for emotionally supporting him around this right now, so is there someone else he can get support from? It can be hard to set a boundary like that! But that kind of clear communication can also be very helpful, and even relieving, for everyone involved. What do you think?
You also said you are concerned that sharing with your boyfriend would result him being "paranoid about having sex in the future". That is possible, but that is also OK. That is a normal response for someone who is not wanting a pregnancy to have after worrying about a potential-pregnancy experience. Are you willing to share more about your concerns about his paranoia? Are you concerned that he will not want to have intercourse anymore? Or will want to change or slow down sexual activity in some way?
Lastly, glad to hear that you are taking your safety and the safety of others seriously!
Thinking of you. Looking forward to hearing your thoughts.