I would say you shouldn't worry too much what your family thinks as sometimes family can be weird about these things, especially if you have an already tense relationship. If you are ready and you feel like you've done everything you need to do in life before you can put this chapter in your life behind you and move on to the next one (because that's what being a parent means, it changes everything and life will never again be as smooth and easy as it once was), then you don't need anyone else's approval for your choices. When my husband and I got pregnant with our first, I was 32, a professional with a good career, in school getting my PhD, had been living on my own for 14 years, financially secure, stable, wonderful husband who she loves, everything, and I still got disapproval from my family (I think because my mum didn't really enjoy parenting and found it stressful herself). And now that I'm 36, still stable, happy, financially secure, great career, happy marriage, she still rolls her eyes when I say we want to have a second. You can't always please everyone and you have to make your own choices.
That said, only you can decide if you're ready, and from reading what you wrote, my guess is it's still a bit of a hasty decision. That doesn't mean you shouldn't have children, but it means make sure you get your ducks in a row first and make all the other commitments you need to make, including financial and legal ones. I don't think you need to be married to have a family together, because some people don't believe in marriage and never want to be married, and that's fine. But if marriage seems like a big commitment right now, and having a baby doesn't, I would give some thought to that. At least a marriage can be annulled if it all goes badly, but once you have a child together, you are stuck together for life, even if you decide to split up years down the line, and you'll have to commit raising your child together, including co-parenting along with new partners as step-parents. You might need to think about why you don't feel ready to get married now, but do feel like you are ready to have a baby together. Because having done both, marriage is definitely the easier of the two.
As you're still in school, I would definitely think about the financial aspects of how you will raise a baby, pay for childcare and also go to school or work once you finish. Childcare is so expensive and it's really hard to take classes, even online, or study while you're caring for a baby or toddler. I had such grand plans for my maternity leave (I was off for a year on paid maternity), that I would get reading and work done for my degree while I was taking time off from grad school, but it was impossible. You're up half the night and then you wake up for the day by 6am and then it's full on all day, and then your baby might go to sleep by 6:30-7pm, but wake up every hour so you only sort of have time to eat dinner and shower, and you finally get to bed by 9-10pm, with 2-3 wake ups a night, and then repeat. It's exhausting. There was no time or energy for studying. When I did go back to school and work, part and then full-time, I needed to pay for childcare (no family who live nearby who could help). I pay about £850 a month or so, depending on the month, which is about $1050 a month. I'm fortunate to work in a field where I make enough that that isn't like my whole paycheck, but you'll want to think if when you finish school, you'll be making enough when you first start to pay for childcare, plus all your other expenses.
That's not to be all negative about it. Being a parent is the best thing I've ever done, but it's damn hard, and I would not have been as ready for it when I was 20 as I was later in life. I enjoyed having fun and being selfish and traveling and spending time with friends and doing all those things in my 20s. I also had no idea how hard and expensive it would be, because no one really talks about these things. I think people like to paint it as being all rosy and fun, but it's work, and I even have a really easy, happy, healthy kid, without any of the challenges that things like special needs or health issues can bring. So I would say, don't let what your family thinks control your choices, but at the same time, it might be worth considering why they might feel the way that do and if that makes sense to you.