What do I do if I'm pregnant?

Hello, I’m 19 years old and I’ve missed my period recently. I decided, maybe because of work and life, I’m just stressed and it’s causing a bit of a stress delay, but I’ve also been finding signs of pregnancy. I know that period and pregnancy signs can be very similar, but I have a regular period and I know my body well enough to say something is not right. But then here’s what’s been bothering me. Assuming I might be pregnant, I want to think ahead rationally and be sure of my actions. I don’t think I’m ready enough to support a child, but I’m very against abortion. Erasing a life that could be or even just the whole idea terrifies me. But I also think that I shouldn’t raise a child so that one day he’d find out he was a mistake and happened by accident. Does anyone have any thoughtful advice or words of comfort? It might help me feel a bit better in the meantime =)