afraid

I am 17 and I had this gut feeling that something was wrong, so I told my boyfriend and he said to take a pregnancy test. I did and the first one was negative, we were super relieved but he told me to take a second one the next morning just to be safe. So I did and it came back positive. We're both super scared and both have big plans for life. I havnt told my parents yet and I am so afraid of what they'll say. I took a third one yesterday and it said positive so I know for sure I am. We're telling them this week but I feel like our lives our ruined and he said we'll be okay and that he wants to be apart of this and won't leave me and wants to be responsible for this but I feel so guilty and I am so afraid. Any advice. We were careful but obviously not careful enough. Please no harsh comments I already have enough regret and fear.