Uy, mama! That's actually a sign na your body is preparing for labor, but since you're still at 37 weeks and a few days, please call your OB or go to the hospital right away to get checked. Hindi kami dapat mag-assume dito, especially with first pregnancy mo. Better safe than sorry talaga!
A few of us moms experienced the same thing, and ang doctors namin nag-monitor lang ng contractions at other signs. Keep an eye out for regular cramping, bleeding, or fluid leaking, and don't wait if you feel anything different. Rooting for you, mama!