Period like cramps

sat

I am FTM. I am 36 weeks currently and have been getting period like cramps in the last 5 days. Its not constant though. It starts suddenly and is there for may be a minute or two and then I am fine. Happens about once or twice daily. Its not unbearable either. Is this related to labor. Should I be concerned about it. Is this a sign that my labor is going to start very soon. Pls advise.