Okay so the baby is coming whether you’re ready or not, so you need to figure something out fast. What’s the actual situation here? Do you live with your parents? Are you renting somewhere that doesn’t allow extra people? Because there’s a difference between “it’s inconvenient” and “there’s literally no physical space.”
If you live with your parents, you need to have a real conversation with them. Yes it might be awkward and yes they might be disappointed, but their grandchild is going to need somewhere to live. If they’re not willing to help, then you need to start looking at other options immediately. Your girlfriend is carrying your child and she deserves to feel safe and supported right now.
Look into affordable housing, see if there are any programs in your area that help young parents, maybe see if her family can take you both in temporarily. You might need to get a second job or a better job to afford your own place. I know that’s not what you want to hear but this is real life now and you have to step up.
Whatever you do, don’t make your girlfriend feel like she’s a burden. She’s literally growing a human being inside her body and that’s hard enough without feeling unwanted. You helped create this situation and now you need to help fix it. Time to be a man about it.