How will this affect us..

So I recently found out I'm expecting with my boyfriend of 3 years, he is 21 I am 20. Initially when I told him he was shocked but supportive, and soon after, we told his parents. They told me to have an abortion in which I do not personally agree with, but do not see a problem with other women doing so. It's just my personal feelings. After telling his parents and hearing their opinions, his opinion started to change and he began to agree with them. We struggled for the first week after finding out, I truly expected us to end things and for me to be a single mom with not much support. But his family apologized to us both and said it was the initial shock but they supported he and I keeping the baby and supported us living with them and helping us out. So our decision has been made, my question is how will this affect mine and his relationship. I know babies can be stressful, especially your first child but I am terrified that he and I are not going to survive this. We love you eachother so much and are best friends but I don't know how adding a baby will change things.. Have any of you ladies experienced this too? I really feel that he and I could be fine but there's no telling what will happen when the baby comes. I really want to be a family and survive this.