it could Def be the start of labor though. mine did that for about 2 days. 10 min apart to 15 min apart. it varied. but the third day they were very consistent and only like 6 min apart. then my water broke so I went it.
I would call. It depends on lots of things like how far away, what number baby for you, if your team is there or has to be called, etc. They can normally assess you over the phone and will tell you to come in when contractions are this long and this far apart. I live an hour away and mine told me not to come in till they were 5 to 6 mins apart with my first baby. Good luck!