Experienced mums i need advice

I am about 27 weeks pregnant with my first. I had never had any idea how i would give birth to a baby, drugs, no drugs, csection or natural but my doctor has said his aim is natural birth etc which I'm happy with but I've seen some stories where women 'rip' down there and need stitches and it really freaks me out. How can you tear and get stitched up. Is your vagina ever the same? Is it just loose and no feelong after forever? Does the tear part hurt and is it noticeable or you dont even know and they tell you? Also do you poo a lot when you push? I'll have my husband there with me and he's a bit freaked out about it too not wanting to see me in pain and stuff. Would you change the way you gave birth of you could?? I need answers and advice to get mentally prepared.