walking = pre-term labor?

FTM. I’ve been trying to work baby boy head down and prepare my body for labor, so I’ve been using my yoga ball since about 28 weeks and I turned 30 weeks on Monday so I’ve added walking two laps around my neighborhood in the evening.

Today I’ve been cramping a bit and I’m nervous I have put myself at risk for pre-term labor. Is walking ok this soon or should I hang it up until I am further along?