Afraid I Am Pregnant

My boyfriend and I had sex on Jan. 22 and 23, both times unprotected. Used withdrawal. I thought I wasn't fertile, but apparently I had counted my days wrong. I got this app along with 3 others and they all say I am fertile right now. I am seriously scared I could get pregnant. I can't let my parents know because I'd probably get kicked out. I don't know how to get an EC without my parents knowing because we are snowed in and my boyfriend does not have much money at the moment. Any advice? I'll be honest, we can't afford to have a child right now. I haven't even graduated high school yet... Just barely 4 more months. And he hasn't been to college yet because of family reasons. I really need some help.