I'm about 3 weeks pregnant and having some difficult mood swings. Normal?

[Autumn L]

I'm pregnant and engaged to the man of my dreams but the past few days have been a roller coaster. I want this baby but I'm so scared. I'm scared of how my family will react, I'm scared for my relationship. Will he and I grow apart from this? We're both pretty young but not too young to start having kids. He's 23 and I'm 20 but I just feel very lost. I'm confused, I should be happy, it's a baby! ya know? We're adults, let's be adults. But I don't know what to do anymore. We don't have stable jobs, we live in a crappy apartment, I feel like my whole life I've had to grow up quickly and this is just added to it. I thought we'd get married, we'd talk about kids, we'd get our few years out of the way and then we would start trying. But this is all backwards. I'm very angry at myself for not being more careful and I'm afraid we can't give this baby what it needs. I'm starting to get depressed and there's just no reason for it. We love eachother. Yes, we're scared but we love eachother and our families will support us no matter what even if they're angry. I just don't know how to get over myself and my dissapointment in this turn of events. I'm never like this, I'm always taking my problems head on. I have to stop. I have to get over this and be happy. Can somebody please tell give me some advice? Do you think this baby will ruin our relationship?