My heart slowed down and felt like it did a flip, sort of like it pumped hard once and then sped back up, is this normal?

Heart rate: There is always variation in heart rate, that may be what you are experiencing. Lots of times when we feel something the heart is normal . Emotion, hormone, adrenaline can all affect the heart. Rarely could be mitral valve prolapse or an unusual rhythm. Urgent cares can do EKGs which will rule out a lot of issues. f/u w/doc, if persistent or recurrs follow w/ cardiologist

Heart: Often younger people will have some irregularity in their heart rate. The safest thing to do is see your doctor and have an EKG and a Holter study to monitor your heart rhythm. All the best.