I think I’m pregnant

My bf and i had sex about 3 weeks ago...mind you that was my first time. I think that i’m pregnant. Or maybe i’m being dramatic. Not only did i break 2 promises to myself but the universe seems to hate me. I dont know for sure because i can’t afford a pregnancy test and i can’t count on my period because before we did it my period was coming 2 weeks earlier for 3 months straight. I’m not ready. I’m not ready for my body to change. Im not ready for carry a child. Im not ready to give up a baby. Im not ready. and if i do take the test and it says pregnant i can’t afford an abortion. I just...i know my body. And my body has been changing over the last 3 weeks. Please help me.