Timing Contractions.. Do I need to go to the Hospital??

I know about the 5-1-1 rule but I'm confused if I should go on and go to the hospital. I've been using an app since 12:30am (it's now 3am) and I'm timing from the start of one contraction and then stopping the timer at the start of the next contraction. They are averaging 3-5 minutes between the start and stop and the pain last for almost 1 minute exactly. But because you stop the timer at the start of the second contraction, the next start time is averaging about 12ish minutes.