18 and accidentally pregnant

To;dr, 18, almost 19, graduating HS, and accidentally got pregnant. keeping the baby with bf of 3 yrs. need tips from people who have/had my same experiences. 
Well, to start off, my boyfriend and I have been dating for three years and are currently in a LDR. He's in TN for school and I'm in Texas finishing up my high school. 
I visited him for a week during spring break in March. We did smoke weed and get drunk, and we ended up having sex (always consensual, don't worry). Anyways, we got to it so quickly that we didn't use a condom, which we realized afterwards. I feel so completely stupid because we were usually so careful. Like nothing went inside ever without it's rubber jacket. Even though that did happen, according to Glow, there was only a 3% chance of getting pregnant on that day, so I didn't think anything of it until recently. On Sunday, 3 weeks after, I took a pregnancy test just for kicks because my friend suggested it might be a good idea and I agreed. It was negative. But today, I took a second this morning because I was now 4 days late. Annnnnd it was positive. 
This was never a position I wanted to put myself in. I had great scholarships for a pretty prestigious school, but I probably will not be able to attend because it's really religious and they probably don't want an unwed pregnant teenager going there because it will look bad for them. So I'm extremely upset about that. 
My boyfriend and I have agreed that adoption and abortion will not be options. We feel like we need to own up to this and not try and pawn off our responsibility on other people. We did this, and it's our job to grow up and take care of it properly. 
Honestly, I would love to hear tips from people who are or have been in my same situation. I'm really at a loss of what to do. I'm going to get a couple more tests today after work, and take them over the next week or 2. I'm hoping it's just a fluke, but I've quite smoking and everything and I'm taking pre-natal vitamins and stuff. I'm just swinging from absolutely completely terrified to almost excited and feeling like "I got this." Just any helpful advice is welcomed.