I think I'm going to shit my pants

It's 5am and I've been up for about an hour and a half. I had to use the bathroom and while I was sitting on the pot, I heard a really loud noise that sounded like a bunch of thunder. I stood up and the sound stopped. It was 5am and I thought it was a thunderstorm, so I just sat back down to wait it out. I sat there for 20 minutes, and my boyfriend got up and went to the living room. I thought it was over and decided to go back to bed. When I was getting into bed, I heard the same noise again. I was so scared, so I jumped back into bed and went under the blankets, then I heard it again. I thought maybe it wasn't a thunderstorm. It was 5:45 and I was so scared that I was going to shit my pants. It happened again at 5:52, 5:55, 6:00, 6:06, 6:15, 6:20. At this point, I've been sitting up in bed, shaking, and sweating. I don't know what it is and it's 6:34 now. I've been waiting for about an hour for it to pass. Please help, I'm afraid to go to sleep.