Baby bursts into crying randomly while sleeping

Anyone had this happen? My baby girl(6weeks) will be sleeping, and she will suddenly just start crying out of the blue and then falls right back to sleep after 5 seconds. It’s really quick. I don’t think she even really wakes up. I don’t think it’s an upset stomach because she takes the bottle fine, burps and isn’t colicky. It doesn’t happen during every nap but when it does, it’s multiple times. I feel horrible when she does it, like something is wrong but idk how to help but talk to her and hold her hand. It’s heartbreaking.